Configuration and Construction

Relay Technical Information CONFIGURATION AND CONSTRUCTION PROTECTIVE CONSTRUCTION 1. Dust Cover Type 2. Flux-Resistant Type cleaning fluid when cleaning. Harmful To protect from dust, these types are The relay is constructed so that flux will substances on the contacts are removed covered, for example, with a plastic case. not enter inside the relay during by gas purging before sealing with. We recommend hand soldering, because automatic soldering. However, cleaning is 4. Sealed capsule type these relays are not constructed to not possible. This type is hermetically sealed with prevent flux and cleaning fluid from 3. Sealed Type ceramic and metal plating. No harmful entering during automatic soldering. Construction is designed to prevent gas or humidity will ever reach the seeping of flux when soldering and contacts. This type cannot be washed. CONSTRUCTION AND CHARACTERISTICS Automatic Automatic Dust Harmful Gas Type Construction Characteristics Soldering Cleaning Resistance Resistance

Most basic construction where the Dust Cover Type case and base (or body) are fitted Take care No Take care No together. Base Terminals are sealed or molded simultaneously. The joint between Yes No Take care No the case and base is higher than Base the surface of the PC board. Flux-Resistant Type

Terminals, case, and base are Yes No Take care No filled with sealing resin.

Sealing resin

Sealed construction with terminals, Sealed Type case and base sealed shut with Yes Yes Yes Yes* sealing resin. Sealing resin

Hermetically sealed construction Sealed capsule type by sealing the metal case and (EP and EV relays No No Yes Yes plate, and the terminal and ceramic only) Solder part, with solder.

*Since the plastic breathes, please do not use in an atmosphere that contains silicone. OPERATIONAL FUNCTION 1. Single Side Stable Type 2. 1 Coil Latching Type 3. 2 Coil Latching Type Relay which turns on when the coil is Relay with latching construction that can Relay with latching construction energized and turns off when de- maintain the on or off state with a pulse composed of 2 coils: set coil and reset energized. input. With one coil, the relay is set or coil. The relay is set or reset by reset by applying signals of opposite alternately applying pulse signals of the polarities. same polarity.

(Schematic example: DS relay)

(Schematic example: DS relay) Schematic example: DS relay

ds_x61_en_relay_technical_information_090712D 1 Configuration and Construction 4. Operation Indication Indicates the set and reset states either electrically or mechanically for easy maintenance. An LED type (HC relay with LED) is available.

LED type, HC relay TERMINAL CONFIGURATION PC board through hole PC board self-clinching Type Plug-in terminal Quick connect terminal Screw terminal terminal terminal

Typical relay

Terminal configuration

Typical relay GQ(AGQ), TX, DS relay TQ relay HJ, HN relay LE, LF, JM relay HE, EP relay type Note: A plug-in solder dual type (HG relay) is also available. MOUNTING METHOD Type Insertion mount Socket mount Terminal socket mount TM type TMP type

Mounting configuration Terminal Socket socket

Typical relay SP-, HC-, HJ-, HL-, JW-, TQ, DS, S relay NC, HC relay HC relay LE, LF relay type SFS-Relays Notes: • Sockets are available for certain PC board relays (S relay, ST relay).

2 ds_x61_en_relay_technical_information_090712D Definition of Relay Terminology DEFINITION OF RELAY TERMINOLOGY

COIL (also referred to as primary or input) 1. Coil Designation Single side stable type 2 coil latching type 1 coil latching type Non-polarized Polarized 4-terminal 3-terminal + — + + — +

or + or —

— + — — — + A black coil represents the energized 4. Nominal Operating Power As the voltage on an unoperated relay is state. For latching relays, schematic The value of power used by the coil at increased, the value at or below which all diagrams generally show the coil in its nominal voltage. For DC coils expressed contacts must function (transfer). reset state. Therefore, the coil symbol is in watts; AC expressed as volt amperes. 7. Drop-Out Voltage also shown for the reset coil in its reset Nominal Power (W or VA) = Nominal (Release or Must Release Voltage) state. Voltage  Nominal Current. As the voltage on an operated relay is 2. Nominal Coil Voltage 5. Coil Resistance decreased, the value at or above which (Rated Coil Voltage) This is the DC resistance of the coil in DC all contacts must revert to their A single value (or narrow range) of type relays for the temperature conditions unoperated position. listed in the catalog. (Note that for certain source voltage intended by design to be 8. Maximum Continuous Voltage applied to the coil or input. types of relays, the DC resistance may be for temperatures other than the The maximum voltage that can be 3. Nominal Operating Current standard 20C 68F.) applied continuously to the coil without The value of current flow in the coil when causing damage. Short duration spikes of 6. Pick-Up Voltage nominal voltage is impressed on the coil. a higher voltage may be tolerable, but (Pull-In Voltage or Must Operate Voltage) this should not be assumed without first checking with the manufacturer.

CONTACTS (secondary or output) 1. Contact Forms switched by the contacts. This value is voltage can be obtained from this graph. Denotes the contact mechanism and the product of switching voltage x For example, if the switching voltage is number of contacts in the contact circuit. switching current, and will be lower than fixed in a certain application, the the maximum voltage and maximum maximum switching current can be 2. Contact Symbols current product. obtained from the intersection between the voltage on the axis and the maximum Form A contacts 5. Maximum Switching Voltage (normally open contacts) switching power. The maximum open circuit voltage which Form B contacts Maximum switching capacity (normally closed contacts) can safely be switched by the contacts. AC and DC voltage maximums will differ 1.000V Form C contacts in most cases. (changeover contacts) 6. Maximum Switching Current ❇Max. Form A contacts are also called N.O. 100V switching The maximum current which can safely power contacts or make contacts. be switched by the contacts. AC and DC DC voltage Form B contacts are also called N.C. current maximums may differ. contacts or break contacts. 7. Maximum Switching Power 10V Form C contacts are also called changeover contacts or transfer contacts. The upper limit of power which can be switched by the contacts. Care should be 10mV 3. MBB Contacts taken not to exceed this value. 10µA 10mA 1A DC current Abbreviation for make-before-break 8. Maximum Switching Capacity contacts. Contact mechanism where Example: Using TX relay at a switching Form A contacts (normally open This is listed in the data column for each type of relay as the maximum value of the voltage of 60V DC, the maximum contacts) close before Form B contacts switching current is 1A. open (normally closed contacts). contact capacity and is an interrelationship of the maximum (*Maximum switching capacity is given 4. Rated Switching Power switching power, maximum switching for a resistive load. Be sure to carefully The design value in watts (DC) or volt voltage, and maximum switching current. check the actual load before use.) amperes (AC) which can safely be The switching current and switching ds_x61_en_relay_technical_information_090712D 3 Definition of Relay Terminology 9. Minimum switching capability voltage-drop method as shown below. In general, for relays with a contact rating This value is a guideline as to the lowest The measuring currents are designated. of 1A or more, measure using the possible level at which it will be possible voltage-drop method at 1A 6V DC. for a low level load to allow switching. V 11. Maximum Carrying Current The level of reliability of this value The maximum current which after closing depends on switching frequency, ambient Measured contact or prior to opening, the contacts can conditions, change in the desired contact safely pass without being subject to resistance, and the absolute value. R A Power temperature rise in excess of their design Please use a relay with AgPd contacts if source (AC or DC) limit, or the design limit of other your needs analog low level loads, temperature sensitive components in the control, or a contact resistance of 100 A : :Ammeter V : Voltmeter R :Variable resistor relay (coil, springs, insulation, etc.). This m or less. Test Currents value is usually in excess of the We recommend that you verify with one Rated Contact Current or Test Current maximum switching current. of our sales offices regarding usage. Switching Current (A) (mA) Less than 0.01 1 12. Capacitance 10. Contact Resistance 0.01 or more and less than 0.1 10 This value is measured between the This value is the combined resistance of 0.1 or more and less than 1 100 terminals at 1kHz and 20C 68°F. the resistance when the contacts are 1 or more 1,000 touching each other, the resistance of the terminals and contact spring. The contact The resistance can be measured with resistance is measured using the reasonable accuracy on a YHP 4328A milliohmmeter. ELECTRICAL PERFORMANCE 1. Insulation Resistance is usually specified, indicating rise time, 5. Release Time (Reset Time) The resistance value between all peak value and fall time. The elapsed time from the initial removal mutually isolated conducting sections of of coil power until the reclosure of the 100 the relay, i.e. between coil and contacts, Form B (normally closed) contacts (last 90 across open contacts and between coil or contact with multi-pole). This time does contacts to any core or frame at ground not include any bounce time. Peak value potential. This value is usually expressed 50 6. Contact Bounce (Time) as “initial insulation resistance” and may 30 decrease with time, due to material Generally expressed in time (ms), this refers to the intermittent switching degradation and the accumulation of Surge breakdown voltage, % 0 0 1.2 50 phenomenon of the contacts which contaminants. Time, µs occurs due to the collision between the • Between coil and contacts 4. Operate Time (Set Time) movable metal parts or contacts, when • Between open contacts The elapsed time from the initial the relay is operated or released. • Between contact sets application of power to the coil, until the • Between set coil and reset coil closure of the Form A (normally open) contacts. (With multiple pole devices the 2. Breakdown Voltage time until the last contact closes.) This (Hi-Pot or Dielectric Strength) time does not include any bounce time. The maximum voltage which can be Coil ON tolerated by the relay without damage for voltage OFF a specified period of time, usually ON Form A measured at the same points as contact OFF Relay release insulation resistance. Usually the stated time for Form value is in VAC (RMS) for one minute Operate time A contact only duration. Form B ON contact OFF 3. Surge Breakdown Voltage Release time The ability of the device to withstand an abnormal externally produced power surge, as in a lightning strike, or other phenomenon. An impulse test waveform

4 ds_x61_en_relay_technical_information_090712D Definition of Relay Terminology MECHANICAL PERFORMANCE AND LIFE 1. Shock Resistance 2) Destructive life or electrical life under repeated operations by applying a pulse train at 1) Functional The vibration which can be withstood by the relay during shipping, installation or the rated voltage to the operating coil. The acceleration which can be tolerated use without it suffering damage, and by the relay during service without 6. Life Curve without causing a change in its operating causing the closed contacts to open for This is listed in the data column for each characteristics. Expressed as an more than the specified time. type of relay. The life (number of acceleration in G’s or displacement, and (usually 10 s) operations) can be estimated from the frequency range. However, test was switching voltage and switching current. 2) Destructive performed a total of six hours, two hours For example, for a DS relay operating at: The acceleration which can be withstood each in three-axis directions. Switching voltage = 125V AC by the relay during shipping or installation 2 3 without it suffering damage, and without Switching current = 0.6A causing a change in its operating The life expectancy is 300,000 characteristics. Usually expressed in 1 operations. However, this value is for a “G”s. However, test was performed a total resistive load. Be sure to carefully check of 18 times, six times each in three-axis the actual load before use. directions. Life Curve 3. Mechanical Life 2 3 1.000 The minimum number of times the relay can be operated under nominal

1 ) 30V DC resistance load conditions (coil voltage, temperature, 4 100 humidity, etc.) with no load on the

contacts. Life (x 10

125V AC resistance load 2. Vibration Resistance 4. Electrical Life 10 The minimum number of times the relay 1) Functional can be operated under nominal The vibration which can be tolerated by conditions with a specific load being the relay during service, without causing switched by the contacts. 12 the closed contacts to open for more than Current (A) the specified time. 5. Maximum Switching Frequency This refers to the maximum switching frequency which satisfies the mechanical

HIGH FREQUENCY CHARACTERISTICS 1. Isolation 3. V.S.W.R. High frequency signals leak through the (Voltage Standing Wave Ratio) stray capacitance across contacts even if High frequency resonance is generated the contacts are separated. This leak is from the interference between the input called isolation. The symbol dB (decibel) signal and reflected (wave) signal. is used to express the magnitude of the V.S.W.R. refers to the ratio of the leak signal. This is expressed as the maximum value to minimum value of the logarithm of the magnitude ratio of the waveform. The V.S.W.R. is 1 when there signal generated by the leak with respect is no reflected wave. It usually becomes to the input signal. The larger the greater than 1. magnitude, the better the isolation. Notes: 2. Insertion Loss 1. Except where otherwise specified, the At the high frequency region, signal tests above are conducted under disturbance occurs from self-induction, standard temperature and humidity resistance, and dielectric loss as well as (15C to 35C 59F to 95F, 25 to from reflection due to impedance 75%). mismatching in circuits. Loss due to any of these types of disturbances is called 2. The coil impressed voltage in the insertion loss. Therefore, this refers to the switching tests is a rectangular wave at magnitude of loss of the input signal. The the rated voltage. smaller the magnitude, the better the 3. The phase of the AC load operation is relay. random.

ds_x61_en_relay_technical_information_090712D 5 General Application Guidelines GENERAL APPLICATION GUIDELINES

A relay may encounter a variety of Therefore, testing over a practical range should be reviewed and determined for ambient conditions during actual use under actual operating conditions is proper use of the relay. resulting in unexpected failure. necessary. Application considerations

SAFETY PRECAUTIONS • Use that exceeds the specification maintaining, or troubleshooting a relay warned that an incorrect connection ranges such as the coil rating, contact (including connecting parts such as may lead to unexpected operation rating and switching life should be terminals and sockets) be sure that the error, abnormal heating, and fire. absolutely avoided. Doing so may lead power is turned off. • If the possibility exists that faulty to abnormal heating, smoke, and fire. • When connecting terminals, please adhesion or contact could endanger • Never touch live parts when power is follow the internal connection diagrams assets or human life, take double applied to the relay. Doing so may in the catalog to ensure that safety precautions and make sure that cause electrical shock. When installing, connections are done correctly. Be operation is foolproof.

[1] METHOD OF DETERMINING SPECIFICATIONS In order to use the relays properly, the to the environmental conditions, and at advance. In the table below, a summary characteristics of the selected relay the same time, the coil conditions, has been made of the points of should be well known, and the conditions contact conditions, and the ambient consideration for relay selection. It may of use of the relay should be investigated conditions for the relay that is actually be used as a reference for investigation to determine whether they are matched used must be sufficiently known in of items and points of caution. Specification item Consideration points regarding selection a) Rating b) Pick-up voltage/current 1)Select relay with consideration for power source ripple. c) Drop-out voltage/current 2)Give sufficient consideration to ambient temperature, for the coil temperature rise d) Maximum continuous voltage/ Coil and hot start. current e) Coil resistance 3)When used in conjunction with semiconductors, additional attention to the f) Impedance application should be taken. Be careful of voltage drops when starting up. g) Temperature rise 1)It is desirable to use a standard product with more than the required number of contacts. 2)It is beneficial to have the relay life balanced with the life of the device it is used in. a) Contact arrangement b) Contact rating 3)Is the contact material matched to the type of load? It is necessary to take care Contacts c) Contact material particularly with low level load. d) Life e) Contact resistance 4)The rated life may become reduced when used at high temperatures. Life should be verified in the actual atmosphere used. 5)Depending on the circuit, the relay drive may synchronize with the AC load. As this will cause a drastic shortening of life should be verified with the actual machine. a) Operate time b) Release time 1)It is beneficial to make the bounce time short for sound circuits and similar Operate time c) Bounce time applications. d) Switching frequency a) Vibration resistance 1)Give consideration to performance under vibration and shock in the use location. Mechanical b) Shock resistance characteristics c) Ambient temperature 2)In particular, when used in high temperature applications, relay with class B or d) Life class F coil insulation may be required. 1)Selection can be made for connection method with plug-in type, PC board type, soldering, tab terminals, and screw fastening type. a) Breakdown voltage b) Mounting method Other items 2)For use in an adverse atmosphere, sealed construction type should be selected. c) Size d) Protective construction 3)When used in adverse environments, use the sealed type. 4)Are there any special conditions?

6 ds_x61_en_relay_technical_information_091112D General Application Guidelines BASICS ON RELAY HANDLING • To maintain initial performance, care applies to plastic sealed type relays, • Do not exceed the usable ambient should be taken to avoid dropping or too.) temperature values listed in the hitting the relay. • Care should be taken to observe catalog. • Under normal use, the relay is correct coil polarity (+, –) for polarized • Use the flux-resistant type or sealed designed so that the case will not relays. type if automatic soldering is to be detach. To maintain initial • Proper usage requires that the rated used. performance, the case should not be voltage be impressed on the coil. Use • Use alcohol based cleaning solvents removed. Relay characteristics cannot rectangular waves for DC coils and when cleaning is to be performed using be guaranteed if the case is removed. sine waves for AC coils. a sealed type relay. Avoid ultrasonic • Use of the relay in an atmosphere at • Be sure the coil impressed voltage cleaning of all types of relays. standard temperature and humidity does not continuously exceed the • As a guide, use a Faston mounting with minimal amounts of dust, SO2, maximum allowable voltage. pressure of 40 to 70N {4 to 7kgf} for H2S, or organic gases is • The rated switching power and life are relays with tab terminals. recommended. given only as guides. The physical • Avoid bending terminals, because it For installation in adverse phenomena at the contacts and may cause malfunction. environments, one of the sealed types contact life greatly vary depending on should be considered. • For proper use, read the main text for the type of load and the operating Please avoid the use of silicone-based details. conditions. Therefore, be sure to resins near the relay, because doing so carefully check the type of load and may result in contact failure. (This operating conditions before use.

[2] PRECAUTIONS REGARDING COIL INPUT Application of the rated voltage is the consideration for changes in coil occur if the voltage applied exceeds the most basic requirement for accurate relay resistance, etc., due to differences in maximum that can be applied operation. Although the relay will work if power supply type, voltage fluctuations, continuously. The following section the voltage applied exceeds the pick-up and rises in temperature. Also, caution is contains precautions regarding coil input. voltage, it is required that only the rated required, because problems such as Please refer to it in order to avoid voltage be applied to the coil out of layer shorts and burnout in the coil may problems.

1. Basic Precautions Regarding Coil • AC operation type damage and welding, with the possible condition of relay operation, For the operation of AC relays, the power occurrence of a false operation self- making it necessary to consider the source is almost always a commercial maintaining condition. current value as 1.5 to 2 times the pick- frequency (50 or 60Hz) with standard For the AC type, there is an inrush up current. Also, because of the voltages of 6, 12, 24, 48, 115, 120, 230 current during the operation time (for the extensive use of relays as limit devices in and 240V AC. Because of this, when the separated condition of the armature, the place of meters for both voltage and voltage is other than the standard impedance is low and a current greater current, and because of the gradual voltage, the product is a special order than rated current flows; for the adhered increase or decrease of current item, and the factors of price, delivery, condition of the armature, the impedance impressed on the coil causing possible and stability of characteristics may create is high and the rated value of current delay in movement of the contacts, there inconveniences. To the extent that it is flows), and because of this, for the case is the possibility that the designated possible, the standard voltages should be of several relays being used in parallel control capacity may not be satisfied. selected. connection, it is necessary to give Thus it is necessary to exercise care. The DC type relay coil resistance varies due Also, in the AC type, shading coil consideration to power consumption. to ambient temperature as well as to its resistance loss, magnetic circuit eddy • DC operation type own heat generation to the extent of current loss, and hysteresis loss exit, and For the operation of DC relays, standards about 0.4%/C, and accordingly, if the because of lower coil efficiency, it is exist for power source voltage and temperature increases, because of the normal for the temperature rise to be current, with DC voltage standards set at increase in pick-up and drop-out greater than that for the DC type. 5, 6, 12, 24, 48, and 100V, but with voltages, care is required. Furthermore, because humming occurs regard to current, the values as (However, for some polarized relays, this when below the pick-up voltage and expressed in catalogs in milliamperes of rate of change is considerably smaller.) when above the rated voltage, care is pick-up current. required with regard to power source However, because this value of pick-up voltage fluctuations. current is nothing more than a guarantee For example, in the case of motor of just barely moving the armature, the starting, if the power source voltage variation in energizing voltage and drops, and during the humming of the resistance values, and the increase in relay, if it reverts to the restored coil resistance due to temperature rise, condition, the contacts suffer a burn must be given consideration for the worst ds_x61_en_relay_technical_information_091112D 7 General Application Guidelines 2. Power Source for Coil Input Figure 1 shows an example of waveform survey of the voltage situation should be • Energizing voltage of AC coil distortion. made using a synchroscope or similar means, and the necessary counter- In order to have stable operation of the If the power source for the relay measures should be taken, and together relay, the energizing voltage should be operating circuit is connected to the same with this determine whether a special basically within the range of +10%/-15% line as motors, solenoids, transformers, relay with suitable excitation of the rated voltage. However, it is and other loads, when these loads characteristics should be used, or make a necessary that the waveform of the operate, the line voltage drops, and change in the DC circuit as shown in voltage impressed on the coil be a sine because of this the relay contacts suffer Figure 2 in which a capacitor is inserted wave. There is no problem if the power the effect of vibration and subsequent to absorb the voltage fluctuations. source is commercially provided power, burn damage. In particular, if a small type but when a stabilized AC power source is transformer is used and its capacity has In particular, when a magnetic switch is used, there is a waveform distortion due no margin of safety, when there is long being used, because the load becomes to that equipment, and there is the wiring, or in the case of household used like that of a motor, depending upon the possibility of abnormal overheating. By or small sales shop use where the wiring application, separation of the operating means of a shading coil for the AC coil, is slender, it is necessary to take circuit and power circuit should be tried humming is stopped, but with a distorted precautions because of the normal and investigated. waveform, that function is not displayed. voltage fluctuations combined with these other factors. When trouble develops, a

Sine wave Approximate keystone wave Waveform with this harmonic included

Figure 1 Distortion in an AC stabilized power source

T Switch 100V AC

24V DC C R Relay coil

Figure 2 Voltage fluctuation absorbing circuit using a condenser

• Power source for DC input • It is desirable to have less than a 5% applied to the coil at the actual load. We recommend that the voltage applied ripple for the reed type relay. to both ends of the coil in DC type relays • For the hinge type relay, a half wave be within 5% of the rated coil voltage. rectifier cannot be used, alone unless As a power source for the DC type relay, you use a smoothing capacitor. The a battery or either a half wave or full wave ripple and the characteristics must be rectifier circuit with a smoothing capacitor evaluated for proper usage. Load is used. The characteristics with regard to • For the hinge type relay, there are the pick-up voltage of the relay will certain applications that may or may change depending upon the type of not use the full wave rectifier on it’s power source, and because of this, in own. Please check specifications with order to display stable characteristics, the the original manufacture. most desirable method is perfect DC. • Coil applied voltage and the drop in In the case of ripple included in the DC voltage power source, particularly in the case of Shown following is a circuit driven by half wave rectifier circuit with a smoothing the same power supply (battery, etc.) capacitor, if the capacity of the capacitor for both the coil and contact. is too small, due to the influence of the Electrical life will be affected by the ripple, humming develops and an drop in voltage in the coil when load is unsatisfactory condition is produced. turned on. With the actual circuit to be used, it is Please verify that the actual voltage is absolutely necessary to confirm the characteristics. It is necessary to give consideration to the use of a DC power source with less than a 5% ripple. Also ordinarily the following must be given thought.

8 ds_x61_en_relay_technical_information_091112D General Application Guidelines .

~

R Relay

Smoothing capacitor Ripple portion

DC portion Emin. Emax. Emean.

Emax. - Emin. Emax. = Maximum value of ripple portion Ripple percentage = x100% Emean. Emin. = Minimum value of ripple portion Emean. = Avarage value of ripple portion Figure 3

3. Maximum Continuous Voltage and Temperature Rise Proper usage requires that the rated and Material Safety Law, this becomes • Pick-up voltage change due to coil voltage be impressed on the coil. Note, 75C 167F. temperature rise (hot start) however, that if a voltage greater than or • Temperature rise due to pulse In DC relays, after continuous passage of equal to the maximum continuous voltage current in the coil, if the current is turned voltage is impressed on the coil, the coil When a pulse voltage with ON time of OFF, then immediately turned ON again, may burn or its layers short due to the less than 2 minutes is used, the coil due to the temperature rise in the coil, the temperature rise. Furthermore, do not temperature rise bares no relationship to pick-up voltage will become somewhat exceed the usable ambient temperature the ON time. This varies with the ratio of higher. Also, it will be the same as using it range listed in the catalog. ON time to OFF time, and compared with in a higher temperature atmosphere. The • Maximum continuous voltage continuous current passage, it is rather resistance/temperature relationship for In addition to being a requirement for small. The various relays are essentially copper wire is about 0.4% for 1C, and relay operation stability, the maximum the same in this respect. with this ratio the coil resistance increases. That is, in order to operate of continuous voltage is an important Current passage time % the relay, it is necessary that the voltage constraint for the prevention of such Temperature rise For continuous passage problems as thermal deterioration or value is 100% be higher than the pick-up voltage and the pick-up voltage rises in accordance deformity of the insulation material, or the ON : OFF = 3 : 1 About 80% with the increase in the resistance value. occurrence of fire hazards. ON : OFF = 1 : 1 About 50% However, for some polarized relays, this In actual use with E-type insulation, when ON : OFF = 1 : 3 About 35% rate of change is considerably smaller. the ambient temperature is 40C 104°F, a temperature rise limit of 80C 176°F is 1 : 1 thought to be reasonable according to the resistance method. However, when Voltage complying with the Electrical Appliance

Time

4. Coil Applied Voltage and Operate Time In the case of AC operation, there is bounce is large, the operate time is 7 to Please be warned that load conditions (in extensive variation in operate time 16ms, with release time in the order of 9 particular when inrush current is large or depending upon the point in the phase at to 18ms. Also, in the case of DC load is close to the load rating) may which the switch is turned ON for coil operation, to the extent of large coil input, cause the working life to shorten and excitation, and it is expressed as a the operating time is rapid, but if it is too slight welding. certain range, but for miniature types it is rapid, the “Form A” contact bounce time for the most part 1/2 cycle. However, for is extended. the somewhat large type relay where

5. Stray Circuits (Bypass Circuits) In the case of sequence circuit upper line is always + and the lower line motor, lamp, etc.). construction, because of bypass flow or (when the circuit is AC, the same alternate routing, it is necessary to take thinking applies). Accordingly the + side Upper side line Contact circuit care not to have erroneous operation or is necessarily the side for making contact Power source lines abnormal operation. To understand this connections (contacts for relays, timers R Load circuit condition while preparing sequence and limit switches, etc.), and the side is Lower side line circuits, as shown in Figure 4, with 2 lines the load circuit side (relay coil, timer coil, Figure 4 Example of a vertically written written as the power source lines, the magnet coil, solenoid coil, sequence circuit ds_x61_en_relay_technical_information_091112D 9 General Application Guidelines Figure 5 shows an example of stray sometimes not be restored to the drop simple by means of a diode to prevent circuits. In Figure 5 (a), with contacts A, out condition. stray circuits, proper application should B, and C closed, after relays R1, R2, and The connections shown in Figure 5 (b) be made. R3 operate, if contacts B and C open, are correctly made. In addition, with there is a series circuit through A, R1, R2, regard to the DC circuit, because it is and R3, and the relays will hum and

A B C D

R1 R2 R3 AB

R1 R2 R3 C

(a) Not a good example (b) Correct example Figure 5 Stray circuits

6. Gradual Increase of Coil Impressed Voltage and Suicide Circuit When the voltage impressed on the coil case of latching relays, using self “Form suicide circuit. In the timing portion for is increased slowly, the relay transferring B” contacts, the method of self coil circuit relay R1, when the timing times out, operation is unstable, the contact for complete interruption is used, but chattering occurs causing trouble. In the pressure drops, contact bounce because of the possibility of trouble initial test (trial production), it shows increases, and an unstable condition of developing, care should be taken. favorable operation, but as the number of contact occurs. This method of applying The circuit shown in Figure 6 causes a operations increases, contact blackening voltage to the coil should not be used, timing and sequential operation using a (carbonization) plus the chattering of the and consideration should be given to the reed type relay, but this is not a good relay creates instability in performance. method of impressing voltage on the coil example with mixture of gradual increase . (use of switching circuit). Also, in the of impressed voltage for the coil and a

Instability point R1aR2a e Switch

R1b R2b X X SW E ON

C R1 C R2 e R1b

R1a

R1a: Form A contact of relay R1 R1: Reed type relay C: Capacitor R1b: Form B contact of relay R1 R2: Reed type relay X: Variable resistance (for time adjustment) Figure 6 “Not a good example”: A timing and sequential operation using a reed type relay

7. Phase Synchronization in AC Load Switching If switching of the relay contacts is material transfer may occur. Therefore, etc., there may be synchronization with synchronized with the phase of the AC check the relay while it is operating in the the power supply phase. power, reduced electrical life, welded actual system. When driving relays with contacts, or a locking phenomenon timers, micro computers and thyristors, (incomplete release) due to contact

Load Ry Load voltage Load Vin. voltage

Vin.

Figure 7

8. Erroneous Operation due to Inductive Interference For long wire runs, when the line for the Therefore, when wiring spans a long control circuit and the line for electric distance please remember that along power use a single conduit, induction with inductive interference, connection voltage, caused by induction from the failure may be caused by a problem with power line, will be applied to the distribution capacity or the device might operation coil regardless of whether or break down due to the influence of not the control signal is off. In this case externally caused surges, such as that the relay and timer may not revert. caused by lightning. 10 ds_x61_en_relay_technical_information_091112D General Application Guidelines 9. Long Term Current Carrying A circuit designed for non-excitation continuously for long periods without For circuits such as these, please use a when left running is desirable for circuits relay switching operation. magnetic-hold type latching relay. If you (circuits for emergency lamps, alarm Continuous, long-term current to the coil must use a single stable relay, use a devices and error inspection that, for will facilitate deterioration of coil sealed type relay that is not easily example, revert only during malfunction insulation and characteristics due to affected by ambient conditions and and output warnings with form B heating of the coil itself. provide a failsafe circuit design that contacts) that will be carrying a current considers the possibility of contact failure or disconnection.

10.Usage with Infrequent Switching Please carry out periodic contact the contacts occurs for long periods, conductivity inspections when the organic membrane may form on the frequency of switching is once or fewer contact surfaces and lead to contact times per month. When no switching of instability.

11.Regarding Electrolytic Corrosion of Coils In the case of comparatively high voltage - Insert the contacts (or switch) in the (Refer to Figure 11) (Common to all coil circuits, when such relays are used in + side of the power source. (Refer to relays) high temperature and high humidity Figure 9) (Common to all relays) Bobbin atmospheres or with continuous passage + – Switch + of current, the corrosion can be said to be Bobbin Relay coil Iron core + – – + R (Insulation the result of the occurrence of electrolytic Relay coil Iron core resistance) corrosion. Because of the possibility of – Switch R (Insulation Figure 11 Judgement: No good open circuits occurring, attention should resistance) be given to the following points. Figure 9 Judgement: Good • In the case of relays provided with a ground terminal, when the ground • The + side of the power source should - When a grounding is not required, terminal is not considered effective, not be connected to the chassis. (Refer to connect the ground terminal to the + making a connection to ground plays Figure 8) (Common to all relays) side of the coil. (Refer to Figure 10) an important role as a method for Bobbin (NF and NR with ground terminal) – + preventing electrolytic corrosion. Switch – Relay coil Iron core + + + R (Insulation + Relay coil Iron core Note: The designation on the drawing Switch resistance) – indicates the insertion of insulation Figure 8 Judgement: Good Bobbin between the iron core and the chassis. In • In the case where unavoidably the + Figure 10 Judgement: Good relays where a ground terminal is side is grounded, or in the case where provided, the iron core can be grounded • When the + side of the power source grounding is not possible. directly to the chassis, but in is grounded, always avoid interting the consideration of electrolytic corrosion, it contacts (and switches) in the + side. is more expedient not to make the connection.

[3] PRECAUTIONS REGARDING CONTACT • Contact waveforms at the time of application and resistance, and the various other The contacts are the most important release), the type of load, frequency of damages which bring about unsuitable elements of relay construction. Contact switching, ambient atmosphere, form of operation, the following items require full performance conspicuously influenced by contact, contact switching speed, and of investigation. contact material, and voltage and current bounce. *We recommend that you verify with one values applied to the contacts (in Because of contact transfer, welding, of our sales offices particular, the voltage and current abnormal wear, increase in contact

1. Basic Precautions Regarding Contact • Voltage, AC and DC exercise care with regard to control to the contact wear. Ordinarily, the When there is inductance included in the capacity. In the case of DC, there is no approximate control capacity is circuit, a rather high counter emf is zero current point such as there is with mentioned in catalogs or similar data generated as a contact circuit voltage, AC, and accordingly, once a cathode arc sheets, but this alone is not sufficient. and since, to the extent of the value of has been generated, because it is difficult With special contact circuits, for the that voltage, the energy applied to the to quench that arc, the extended time of individual case, the maker either contacts causes damage with the arc is a major cause. In addition, due estimates from the past experience or consequent wear of the contacts, and to the direction of the current being fixed, makes test on each occasion. Also, in transfer of the contacts, it is necessary to the phenomenon of contact shift, as catalogs and similar data sheets, the noted separately below, occurs in relation control capacity that is mentioned is ds_x61_en_relay_technical_information_091112D 11 General Application Guidelines limited to resistive load, but there is a frequency, ambient conditions, change in important influence. For example, when broad meaning indicated for that class of the desired contact resistance, and the the load is either a motor or a lamp, to the relay, and ordinarily it is proper to think of absolute value. Please use relays with extent of the inrush current at the time of current capacity as that for 125V AC AgPd contacts when minute analog load closing the circuit, wear of the contacts, circuits. control or contact resistance no higher and the amount of contact transfer Minimum applicable loads are given in than 100 m is desired (for measure- increase, and contact welding and the catalog; however, these are only ment and wireless applications, etc.). contact transfer make contact separation provided as a guide to the lower limit that • Current impossible. the relay is able to switch and are not The current at both the closing and guaranteed values. The level of reliability opening time of the contact circuit exerts of these values depends on switching

2. Characteristics of Common Contact Materials Characteristics of contact materials are given below. Refer to them when selecting a relay. Electrical conductivity and thermal conductivity are the highest of all metals. Exhibits low contact resistance, is Ag inexpensive and widely used. A disadvantage is it easily develops a sulfide film in a sulfide atmosphere. Care is (silver) required at low voltage and low current levels.

AgSnO2 Exhibits superior welding resistance characteristics equal or better than AgCdO. (silver-tin) Like silver, it easily develops a sulfide film in a sulfide atmosphere. Contact Hardness and melting point are high, arc resistance is excellent, and it is highly resistant to material transfer. AgW Material However, high contact pressure is required. Furthermore, contact resistance is relatively high and resistance to (silver-tungsten) corrosion is poor. Also, there are constraints on processing and mounting to contact springs. AgNi Equals the electrical conductivity of silver. Excellent arc resistance. (silver-nickel) AgPd At standard temperature, good corrosion resistance and good sulfidation resistance. However, in dry circuits, (silver-palladium) organic gases adhere and it easily develops a polymer. Gold clad is used to prevent polymer buildup. Expensive. Combines perfect corrosion resistance and hardness. As plated contacts, used for relatively light loads. In an Rh plating organic gas atmosphere, care is required as polymers may develop. Therefore, it is used in hermetic sealed (rhodium) relays (reed relays, etc.). Expensive. Au with its excellent corrosion resistance is pressure welded onto a base metal. Special characteristics are Au clad uniform thickness and the nonexistence of pinholes. Greatly effective especially for low level loads under relatively (gold clad) Surface adverse atmospheres. Often difficult to implement clad contacts in existing relays due to design and installation. Finish Au plating Similar effect to Au clad. Depending on the plating process used, supervision is important as there is the (gold plating) possibility of pinholes and cracks. Relatively easy to implement gold plating in existing relays. Au flash plating Purpose is to protect the contact base metal during storage of the switch or device with built-in switch. However, (gold thin-film plating) a certain degree of contact stability can be obtained even when switching loads. 0.1 to 0.5m

3. Contact Protection • Counter EMF contained in the air and causes black Figure 12 (b) at the instant the inductive When switching inductive loads with a deposits (oxides, carbides) to develop on load is switched off. The counter emf DC relay such as relay sequence circuits, the contacts. This may result in contact passes through the power supply line and DC motors, DC clutches, and DC failure. reaches both contacts. solenoids, it is always important to Generally, the critical dielectric ON OFF absorb surges (e.g. with a diode) to Peak voltage E breakdown voltage at standard protect the contacts. + – meter 0 temperature and pressure in air is about – Several hundred When these inductive loads are switched + to several 200 to 300 volts. Therefore, if the counter E R e thousand volts off, a counter emf of several hundred to – emf exceeds this, discharge occurs at the + di 1 2 several thousand volts develops which e = –Ldt contacts to dissipate the energy ( /2Li ) can severely damage contacts and (a) (b) stored in the coil. For this reason, it is greatly shorten life. If the current in these Figure 12 Example of counter emf and actual desirable to absorb the counter emf so loads is relatively small at around 1A or measurement that it is 200V or less. less, the counter emf will cause the In Figure 12 (a), a counter emf (e = –L di/ ignition of a glow or arc discharge. The dt) with a steep waveform is generated discharge decomposes organic matter across the coil with the polarity shown in

• Material transfer phenomenon lock as if they were welded together. This Contact protection circuits and contact Material transfer of contacts occurs when often occurs in circuits where sparks are materials resistant to material transfer one contact melts or boils and the contact produced at the moment the contacts such as AgSnO2, AgW or AgCu are used material transfers to the other contact. As “make” such as when the DC current is as countermeasures. Generally, a the number of switching operations large for DC inductive or capacitive loads concave formation appears on the increases, uneven contact surfaces or when the inrush current is large cathode and a convex formation appears develop such as those shown in Figure (several amperes or several tens of on the anode. For DC capacitive loads 13. After a while, the uneven contacts amperes). (several amperes to several tens of

12 ds_x61_en_relay_technical_information_091112D General Application Guidelines amperes), it is always necessary to conduct actual confirmation tests.

Figure 13 Material transfer of contacts

• Contact protection circuit Use of contact protective devices or that incorrect use will result in an adverse protection circuits can suppress the effect. Typical contact protection circuits counter emf to a low level. However, note are given in the table below. (G: Good, NG: No Good, C: Conditional) Application Circuit Features/Others Devices Selection AC DC

Contact If the load is a timer, leakage current flows As a guide in selecting c and r, through the CR circuit causing faulty c: 0.5 to 1F per 1A contact current operation. r: 0.5 to 1 per 1V contact voltage C* G rc * If used with AC voltage, be sure the Values vary depending on the properties impedance of the load is sufficiently of the load and variations in relay Inductive load smaller than that of the CR circuit characteristics. Capacitor “c” acts to CR circuit suppress the discharge the moment the Contact If the load is a relay or solenoid, the contacts open. Resistor “r” acts to limit the release time lengthens. Effective when current when the power is turned on the r GGconnected to both contacts if the power next time. Test to confirm. Use a capacitor “c” with a breakdown voltage of 200 to c supply voltage is 24 or 48V and the voltage across the load is 100 to 200V. 300V. Use AC type capacitors (non- Inductive load polarized) for AC circuits. The diode connected in parallel causes Use a diode with a reverse breakdown the energy stored in the coil to flow to the voltage at least 10 times the circuit voltage Contact coil in the form of current and dissipates it and a forward current at least as large as as joule heat at the resistance component the load current. In electronic circuits Diode circuit NG G Diode of the inductive load. This circuit further where the circuit voltages are not so high, delays the release time compared to the a diode can be used with a reverse

Inductive load CR circuit. (2 to 5 times the release time breakdown voltage of about 2 to 3 times listed in the catalog) the power supply voltage.

Contact Diode and Use a zener diode with a zener voltage Effective when the release time in the zener diode NG G about the same as the power supply diode circuit is too long. circuit voltage. Inductive load Using the stable voltage characteristics of the varistor, this circuit prevents Contact excessively high voltages from being applied across the contacts. This circuit Varistor circuit G G also slightly delays the release time. _ Varistor Effective when connected to both contacts if the power supply voltage is 24 to 48V Inductive load and the voltage across the load is 100 to 200V.

• Avoid using the protection circuits shown Contact Contact in the figures on the right. Although DC inductive loads are usually Power No good Power No good C supply C

supply Load

more difficult to switch than resistive Load loads, use of the proper protection circuit will raise the characteristics to that for resistive loads. Although extremely effective in arc suppression Although extremely effective in arc suppression as the contacts open, the contacts are as the contacts open, the contacts are susceptible to welding since energy is stored in susceptible to welding since charging current “C” when the contacts open and short-circuit flows to “C” when the contacts close. current flows from “C” when the contacts close.

• Mounting the protective device • Abnormal corrosion during high switching. Therefore, care is required in In the actual circuit, it is necessary to frequency switching of DC loads circuits where sparks are generated at a locate the protective device (diode, (spark generation) high frequency. resistor, capacitor, varistor, etc.) in the If, for example, a DC valve or clutch is immediate vicinity of the load or contact. switched at a high frequency, a blue- If located too far away, the effectiveness green corrosion may develop. This of the protective device may diminish. As occurs from the reaction with nitrogen a guide, the distance should be within and oxygen in the air when sparks (arc 50cm. discharge) are generated during ds_x61_en_relay_technical_information_091112D 13 General Application Guidelines 4. Cautions on Use Related to Contacts • Connection of load and contacts This prevents high voltages from a risk of shorting the power supply when Connect the load to one side of the power developing between contacts. If contacts relatively close contacts short. supply as shown in Figure 14 (a). are connected to both side of the power Connect the contacts to the other side. supply as shown in Figure 14 (b), there is

Ry E (a) E (b)

Ry Ry Ry

(a) Good example (b) Bad example

Figure 14

• Dummy Resistor low, poor conduction is often the result. load to intentionally raise the load current Since voltage levels at the contacts used One method to increase reliability is to reaching the contacts. in low current circuits (dry circuits) are add a dummy resistor in parallel with the • Avoid circuits where shorts occur 2) Even if the three N.C., N.O., and COM 3) A forward and reverse motor rotation between Form A and B contacts contacts are connected so that they circuit using switching of form A and B 1) The clearance between form A and B short, a circuit must never be designed to contacts must never be designed. contacts in compact control components allow the possibility of burning or is small. The occurrence of shorts due to generating an overcurrent. arcing must be assumed.

R1

R1 N.C. N.O. Push-button switch COM M Load R R Relay coil Load R2 Commercial AC power Home AC generator R2

1) R1, R2: Contacts for R 2) 3) R1,R2: Contacts for R R: Double pole relay R: Double pole relay

Figure 15 Bad example of Form A and B use

• Shorts between different electrodes Although there is a tendency to select miniature control components because of the trend toward miniaturizing electrical control units, care must be taken when selecting the type of relay in circuits where different voltages are applied between electrodes in a multi-pole relay, especially when switching two different power supply circuits. This is not a problem that can be determined from sequence circuit diagrams. The construction of the control component itself must be examined and sufficient margin of safety must be provided especially in creepage between electrodes, space distance, presence of barrier, etc.

14 ds_x61_en_relay_technical_information_091112D General Application Guidelines • Type of load and inrush current Particularly for loads with inrush currents, between typical loads and their inrush The type of load and its inrush current measure the steady state and inrush currents. characteristics, together with the current. Then select a relay which Also, verify the actual polarity used since, switching frequency, are important provides an ample margin of safety. The depending on the relay, electrical life is factors which cause contact welding. table on the right shows the relationship affected by the polarity of COM and NO. Type of load Inrush current Resistive load Steady state current Solenoid load 10 to 20 times the steady state current Motor load 5 to 10 times the steady state current Incandescent lamp load 10 to 15 times the steady state current Mercury lamp load Approx. 3 times the steady state current Sodium vapor lamp load 1 to 3 times the steady state current Capacitive load 20 to 40 times the steady state current Transformer load 5 to 15 times the steady state current

Load Inrush Current Wave and Time (1) Incandescent Lamp Load (2) Mercury Lamp Load (3) Fluorescent Lamp Load i/iO approx. 3 times i/iO approx. 5 to 10 times

i io Contacts L i io

i io C

Incandescent lamp 3 to 5 minutes The discharge tube, transformer, choke coil, (for high power factor type) capacitor, etc., are combined in common 10 seconds discharge lamp circuits. Note that the inrush or less Approx. 1/3 second current may be 20 to 40 times, especially if Inrush current/rated current: the power supply impedance is low in the high power factor type. i/io] 10 to 15 times

(4) Motor Load i/iO approx. 5 to 10 times (5) Solenoid Load (6) Electromagnetic Contact Load (7) Capacitive Load i/iO approx.10 to 20 times i/iO approx. 3 to 10 times i/iO approx. 20 to 40 times

i io

Free Lock Load i io i i Steady 0.2 to 0.5 second Starting state Braking

G Conditions become more harsh if plugging or inching i performed since state transitions are repeated. 0.07 to 0.1 second G When using a relay to control a DC motor and brake, the on time inrush current, steady state current and off Note that since inductance is great, the arc 1 to 2 cycles time brake current differ depending on whether the lasts longer when power is cut. The contact (1/60 to 1/30 seconds) load to the motor is free or locked. In particular, with may beome easily worn. non-polarized relays, when using from B contact of from contact for the DC motor brake, mechanical life 1/2 to 2 cycles (1/120 to 1/30 second might be affected by the brake current. Therefore, please verify current at the actual load.

• When using long wires • Electrical life at high temperatures If long wires (100 to 300m) are to be used Verify at the actual load since electrical in a relay contact circuit, inrush current Equivalent circuit + life may be affected by use at high may become a problem due to the stray temperatures. capacitance existing between wires. Add Contacts a resistor (approx. 10 to 50) in series Stray capacitance with the contacts. Added resistor Wire of wire 10 to 50 Ω (100 to 300 m)

ds_x61_en_relay_technical_information_091112D 15 General Application Guidelines [4] PRECAUTIONS REGARDING LATCHING RELAYS

• Latching relays are shipped from the • Avoid using the following circuit since Relay Type Terminal Nos. factory in the reset state. A shock to the self-excitation at the contacts will inhibit 1c — relay during shipping or installation the normal keep state DS 2c 15 & 16 may cause it to change to the set state. . 4c * Therefore, it is recommended that the Flat 5 & 6 relay be used in a circuit which NC initializes the relay to the required state RLb RLa Slim 3 & 4 (set or reset) whenever the power is ST * turned on. SP 2 & 4 RL RL: Latching relay Notes: Load • Avoid impressing voltages to the set RLa: Form A contacts of RL 1. DS4c and ST relays are constructed so that coil and reset coil at the same time. RLb: Form B contacts of RL the set coil and reset coil are separated for high insulation resistance. Bad example • Connect a diode as shown since 2. DSP, TQ, S relays are not applicable due to latching may be compromised when • Four-terminal latching relay polarity. the relay is used in the following • Two Coil Latch Induction Voltage circuits. In the 2-coil latching type circuit as shown below, one terminal at one end of the set Each coil in a 2-coil latch relay is wound - If set coils or reset coils are to be coil and one terminal at one end of the with a set coil and a reset coil on the connected together in parallel, reset coil are connected in common and same iron cores. Accordingly, induction connect a diode in series to each voltages of the same polarity are applied voltage is generated on the reverse side coil. Figure 16 (a), (b) to the other side for the set and reset coil when voltage is applied and shut off - Also, if the set coil of a relay and the operations. In this type of circuit, short 2 to each coil. Although the amount of reset coil of another relay are terminals of the relay as noted in the induction voltage is about the same as connected in parallel, connect a table. This helps to keep the insulation the rated relay voltage, you must be diode to the coils in series. Figure 16 high between the two winding. careful of the reverse bias voltage when (c) driving transistors. - If the set coil or reset coil is to be Set switch Reset switch connected in parallel with an

inductive load (e.g. another Set coil Reset coil electromagnetic relay coil, motor, transformer, etc.), connect a diode to the set coil or reset coil in series. • Minimum pulse width Figure 16 (d) As a guide, make the minimum pulse • Use a diode having an ample margin of width in order to set or reset a latching safety for repeated DC reverse voltage relay at least 5 times the set time or reset and peak reverse voltage applications time of each product and apply a and having an average rectified current rectangular-wave rated voltage. Also, greater than or equal to the coil current. please verify operation. Please inquire if • Avoid applications in which conditions you cannot obtain a pulse width of at include frequent surges to the power least 5 times the set (reset) time. Also, supply. please inquire regarding capacitor drive.

(a) Parallel connection of set coils (b) Parallel connection of reset coils (+) (+)

S1 S2 S3 S1 S2 S3

Reset Reset coil Reset coil coil Reset coil

Set coil Set coil Set coil Set coil

(–) (–) Diode connection Diode connection Diode connection Diode connection

(c) Parallel connection of set and reset coils (d) Circuit with inductive load in parallel with (+) the set coil or reset coil (+)

S1 S2 S3 S

Reset AC or coil Reset coil Motor DC Common relay Set coil M coil Set coil Set or reset coil

(–) (–) Diode connection Diode connection Diode connection Figure 16

16 ds_x61_en_relay_technical_information_091112D General Application Guidelines

[5] HANDLING CAUTIONS FOR TUBE PACKAGING Some types of relays are supplied in tube packaging. If you remove any relays from Slide in the plug the tube packaging, be sure to slide the stop plug at one end to hold the remaining relays firmly together so they Stop plug would not move in the tube. Failing to do this may lead to the appearance and/or performance being damaged.

[6] AMBIENT ENVIRONMENT 1. Ambient Temperature and direction of the shock to a perpendicular The humidity range varies with the Atmosphere angle. temperature. Use within the range Be sure the ambient temperature at the Also, if the relay will be subject to indicated in the graph. installation does not exceed the value continual vibration (trains, etc.), do not Humidity, % R.H. listed in the catalog. Furthermore, use it with a socket. We recommend that environmentally sealed types (plastic you solder directly to the relay terminals. 85 sealed type) should be considered for Tolerance range 5. Influence of External Magnetic applications in an atmosphere with dust, Fields sulfur gases (SO2, H2S), or organic Avoid (Avoid freezing when condensation gases. Permanent magnets are used in reed used at temperatures when used at relays and polarized relays, and their lower than 0°C 32°F) temperatures 2. Silicone Atmosphere higher than 0°C 32°F ) movable parts are constructed of ferrous 5 Silicone-based substances (silicone materials. For this reason, when a –40 0 +85 –40 +32 +185 rubber, silicone oil, silicone-based magnet or permanent magnet in any Temperature, °C°F coating material, silicone caulking other large relay, transformer, or speaker (The allowable temperature depends on compound, etc.) emit volatile silicone is located nearby, the relay the switch.) gas. Note that when silicone is used near characteristics may change and faulty relay, switching the contacts in the operations may result. The influence • Condensation will occur inside the presence of its gas causes silicone to depends on the strength of the magnetic switch if there is a sudden change in adhere to the contacts and may result in field and it should be checked at the ambient temperature when used in an contact failure (in plastic sealed types, installation. atmosphere of high temperature and too). high humidity. This is particularly likely 6. Usage, Storage, and Transport to happen when being transported by In this case, use a substitute that is not Conditions ship, so please be careful of the silicone-based. During usage, storage, or transportation, atmosphere when shipping. 3. NOx Generation avoid locations subject to direct sunlight Condensation is the phenomenon When a relay is used in an atmosphere and maintain normal temperature, whereby steam condenses to cause high in humidity to switch a load which humidity, and pressure conditions. water droplets that adhere to the switch easily produces an arc, the NOx created The allowable specifications for when an atmosphere of high by the arc and the water absorbed from environments suitable for usage, storage, temperature and humidity rapidly outside the relay combine to produce and transportation are given below. changes from a high to low temperature or when the switch is nitric acid. This corrodes the internal • Temperature metal parts and adversely affects quickly moved from a low humidity The allowable temperature range differs operation. location to one of high temperature and for each relay, so refer to the relay’s humidity. Please be careful because Avoid use at an ambient humidity of individual specifications. condensation can cause adverse 85%RH or higher (at 20C 68F). If use at In addition, when transporting or storing conditions such as deterioration of high humidity is unavoidable, consult us. relays while they are tube packaged, insulation, coil cutoff, and rust. 4. Vibration and Shock there are cases when the temperature • Condensation or other moisture may If a relay and magnetic switch are may differ from the allowable range. freeze on the switch when the mounted next to each other on a single In this situation, be sure to consult the temperatures is lower than 0C 32F. plate, the relay contacts may separate individual specifications. This causes problems such as sticking momentarily from the shock produced • Humidity of movable parts or operational time when the magnetic switch is operated lags. 5 to 85 % R.H. and result in faulty operation. • The plastic becomes brittle if the switch Countermeasures include mounting them • Pressure is exposed to a low temperature, low on separate plates, using a rubber sheet 86 to 106 kPa humidity environment for long periods to absorb the shock, and changing the of time. ds_x61_en_relay_technical_information_091112D 17 General Application Guidelines • Storage for extended periods of time - Please use promptly once the anti- Panasonic affixes a cautionary label (including transportation periods) at humidity pack is opened (Signal to the vacuum-sealed bag in which high temperatures or high humidity relay: with in 3 days, Max. 30C the products are delivered. levels or in atmospheres with organic 86°F/60%RH). If left with the pack gases or sulfide gases may cause a open, the relay will absorb moisture - Note: sulfide film or oxide film to form on the which will cause thermal stress when Please note that the products must surfaces of the contacts and/or it may reflow mounting and thus cause the be mounted within the time limit interfere with the functions. Check out case to expand. As a result, the seal specified on the bag. The time limit the atmosphere in which the units are may break. given on the bag varies for the to be stored and transported. - When storing for a long period after different kinds of surface-mount • In terms of the packing format used, opening the anti-humidity pack, you terminal type products. make every effort to keep the effects of must take measures to prevent 7. Vibration, Impact and Pressure moisture, organic gases and sulfide humidity, for example, by storing in when Shipping gases to the absolute minimum. the open location of a promptly re- • Since the SMD type is sensitive to sealed anti-humidity pack after it is When shipping, if strong vibration, impact humidity it is packaged with tightly used or in a humidity-controlled or heavy weight is applied to a device in sealed anti-humidity packaging. desicator. You may also store it in an which a relay is installed, functional However, when storing, please be anti-humidity bag to which silica gel damage may occur. Therefore, please careful of the following: has been added. package in a way, using shock absorbing - To avoid incorrect handling of our material, etc., so that the allowable range moisture-sensitive products, for vibration and impact is not exceeded.

[7] ENVIRONMENTALLY SEALED TYPE RELAYS Sealed type (plastic sealed type, etc.) 1. Operating Environment 2. Cleaning relays are available. They are effective Plastic sealed type relays are not suited When cleaning a printed circuit board when problems arise during PC board for use in environments that especially after soldering, we recommend using mounting (e.g. automatic soldering and require air tightness. Although there is no alcohol based cleaning fluids. Please cleaning). They also, of course, feature problem if they are used at sea level, avoid ultrasonic cleaning. The ultrasonic excellent corrosion resistance. Note the avoid atmospheric pressures beyond energy from this type of cleaning may cautions below regarding the features 9610kPa. Also avoid using them in an cause coil line breakage and light sticking and use of environmentally sealed type atmosphere containing flammable or of contacts. relays to avoid problems when using explosive gases. them in applications.

[8] MOUNTING CONSIDERATIONS 1. Top View and Bottom View Form B contacts while the coil is not excited is greatly affected by the Relays used for PC boards, especially n tio mounting direction of the relay. ra the flat type relays, have their top or ib V bottom surface indicated in the terminal • Contact reliability wiring diagrams. Mounting the relay so the surfaces of its Relay with terminals contacts (fixed contacts or movable viewed from the bottom contacts) are vertical prevents dirt and (terminals cannot be dust as well as scattered contact material seen from the top) (produced due to large loads from which Relay with terminals arcs are generated) and powdered metal viewed from the top (all from adhering to them. terminals can be seen Furthermore, it is not desirable to switch from the top) both a large load and a low level load Note during PC board with a single relay. The scattered contact pattern design (NL, Vibration material produced when switching the NC) large load adheres to the contacts when 2. Mounting Direction switching the low level load and may Mounting direction is important for cause contact failure. Therefore, avoid optimum relay characteristics. mounting the relay with its low level load contacts located below the large load • Shock resistance contacts. It is ideal to mount the relay so that the movement of the contacts and movable parts is perpendicular to the direction of vibration or shock. Especially note that the vibration and shock resistance of 18 ds_x61_en_relay_technical_information_091112D General Application Guidelines 3. Adjacent Mounting temperature of the relay does not exceed • Influence of adjacent mounting of When many relays are mounted close the value listed in the catalog. polarized relays together, abnormally high temperatures When polarized relays are mounted close may result from the combined heat together, their characteristics change. generated. Mount relays with sufficient Since the affect of adjacent mounting spacing between them to prevent heat differs according to the type of relay, refer buildup. to the data for the particular type. This also applies when a large number of 4. Panel Mounting boards mounted with relays are installed • Do not remove the cover. It has a as in a card rack. Be sure the ambient special function. (It will not come off under normal handling.)

[9] METHOD OF MOUNTING AND LEAD WIRES CONNECTION 1. Mounting Method • The socket should be pushed through 2. Connection of Lead Wires The direction of mounting is not the opening in the mounting panel until • When making the connections, specifically designated, but to the extent the projections on the side of the depending upon the size of load, the possible, the direction of contact mounting bracket extend out over the wire cross-section should be at least as movement should be such that vibration back surface. large as the values shown in the table and shock will not be applied. below. When a terminal socket is used Permissible current Cross-section (A) (mm2) After drilling the mounting holes, the 2 0.2 terminal socket should be mounted 3 0.3 making certain the mounting screws are 5 0.5 not loose. DIN standard sockets are 7.5 0.75 available for one-touch mounting on DIN • When all four of the projections are rail of 35mm 1.378 inch width. visible from the back side of the 12.5 1.25 mounting panel, the mounting is 15 2 When reversible terminal sockets are completed and the socket is fastened. 20 2 used • To remove the socket, the projections 30 3.5 • The reversible terminal sockets (HC, on the side of the mounting bracket • When the terminal socket uses screw HL socket) are for one-touch mounting. should be pushed inward and at the fastening connections, either pressure (A panel thickness of 1 to 2mm .039 to same time the body of the socket terminals or other means should be .079 inch should be used.) should be pushed lightly from the back used to make secure fastening of the side. The socket can then be removed wire. from the panel. • To prevent damage and deformity, please use a torque within the following range when tightening the push screw block of the terminal socket. Screw Torque 1.47 to 1.666 N·m M4.5 (15 to 17 kgf·cm) 1.176 to 1.37 N·m M4 (12 to 14 kgf·cm) 0.784 to 0.98 N·m (8 M3.5 to 10 kgf·cm) 0.49 to 0.69 N·m(5 to M3 7 kgf·cm)

ds_x61_en_relay_technical_information_091112D 19 General Application Guidelines

[10]CAUTIONS FOR USE–CHECK LIST Item To check 1)Is the correct rated voltage applied? 2)Is the applied coil voltage within the allowable continuous voltage limit? 3)Is the ripple in the coil voltage within the allowable level? 4)For voltage applied to a polarized coil, is polarity observed? 5)When hot start is required, is the increase in coil resistance resulting from coil temperature rise taken into account in setting coil voltage? Coil Drive Input 6)Is the coil voltage free from momentary drop caused by load current? (Pay special attention for self-holding relays.) 7)Is supply voltage fluctuation taken into account when setting the rated coil voltage? 8)The relay status may become unstable if the coil voltage (current) is gradually increased or decreased. Was the relay tested in a real circuit or with a real load? 9)When driving with transistors, did you consider voltage drops? 1)Is the load rated within the contact ratings? 2)Does the load exceed the contacts’ minimum switching capacity? 3)Special attention is required for contact welding when the load is a lamp, motor, solenoid, or electromagnetic contractor. Was the relay tested with a real load? 4)A DC load may cause contact lock-up due to large contact transfer. Was the relay tested with a real load? 5)For an inductive load, is a surge absorber used across the contacts? 6)When an inductive load causes heavy arc discharge across the relay contacts, the contacts may be corroded by chemical reaction with nitrogen in the atmosphere. Was the relay tested with a real load? Load (Relay contacts) 7)Platinum contacts may generate brown powder due to a catalyzer effect or vibration energy. Was the relay tested with a real load? 8)Is the contact switching frequency below the specification? 9)When there are more than two sets of contacts (2T) in a relay, metallic powder shed from one set of contacts may cause a contact failure on the other set (particularly for light loads). Was the relay tested in a real load? 10)A delay capacitor used across relay contacts may cause contact welding. Was the relay tested with a real load? 11)For an AC relay, a large contact bounce may cause contact welding. Was the relay tested in a real circuit or with a real load? 12)A high voltage may be induced at transformer load. Was the relay tested with a real load? 1)Does circuit design take into account electrolytic corrosion of the coil? 2)Are transistors and other circuit components protected rom counter electromotive force that develops across the relay coil? 3)Is the circuit designed so the relay coil is left deenergized while the relay is inactive for long period of time? 4)Is the relay operated within the ratings approved by the relevant international standard (if compliance is required)? 5)Is the circuit protected from malfunction when the relay’s activation and/or deactivation time varies considerably? 6)Is the circuit protected from malfunctions that might result from relay contact bounce? 7)Is the circuit protected from malfunction when a high-sensitivity latching type relay is to be used? 8)When there are two or more sets of contacts (2T) in a relay, arc discharges from load switching may cause short Circuit Design circuits across the two or more sets of contacts. Is the circuit designed to suppress such arc discharges? 9)Item 8 above also requires special attention when loads are supplied from separate power sources. 10)Does the post-installation insulation distance comply with the requirement of the relevant international standard or the Electrical Appliance and Material Control Law? 11)Is the circuit protected from malfunction when the relay is to be driven by transistors? 12)When the SCR is used for on/off control, the relay activation tends to synchronize with the line frequency, resulting in an extremely shortened life. Was the relay tested in a real circuit or with a real load? 13)Does the PC board design take into account use of on-board relay? 14)RF signals may leak across relay’s open contacts. Check for adequate contact isolation and use RF relays as needed

20 ds_x61_en_relay_technical_information_091112D General Application Guidelines

Item To check 1)Is the ambient temperature in the allowable operating temperature range? 2)Is the humidity in the allowable humidity range? 3)Is the operating atmosphere free from organic and sulfide gases? 4)Is the operating atmosphere free from silicone gas? Depending on the load type, silicone gas may cause a black substance to from on the contacts, leading to contact failure.

Operating 5)Is the operating atmosphere free from excessive airborne dust? Environment 6)Is the relay protected from oil and water splashes? 7)Is the relay protected from vibration and impact which may cause poor contact with the socket? 8)Is ambient vibration and impact below the level allowable for the relay? 9)Is the relay free from mechanical resonance after it is installed in position? 10)Is insulation coating applied to the relay along with the PC board? Depending on the load type, a black substance may form to cause contact failure. 1)Is the relay protected from solder chips and flux when it is manually soldered? 2)Are preparations for flux application and automatic soldering complete? 3)Is the PC board cleaning process designed to minimize adverse affects to the relays? 4)Are adequate separations provided between polarized or reed relays to prevent magnetic coupling? 5)Are the relay terminals free from stress in the socket? 6)Polarized relay’s characteristics may be affected by strong external magnetic field. Are the relays installed away from such fields? Installation and 7)If very long leads (100 to 300 meters) are used to connect the load, the stray capacity existing across the leads may Connection cause the inrush current. Was the relay tested with a real load? 8)Unless otherwise specified, all relay terminals should be soldered at 250C 482°F within 5 sec. or at 350C 662°F within 3 sec. 9)A badly warped PC board can cause stress to the relay terminals which may lead to degraded relay characteristics. 10)Glass shot should not be used to clean the PC board of solder flux. This may cause relay malfunction due to glass powder becoming lodged in the relay’s internal structure. 11)Relays should always be used with their plastic shields installed, or degraded relay performance may result. 12)Do not cut away any relay terminal as the stress may cause degraded relay performance. 1)Is the relay subject to freezing or condensation (especially when shipping)? 2)Is the temperature in the allowable temperature range? 3)Is the humidity in the allowable humidity range?

Storage and 4)Is the storing atmosphere free from organic and sulfide gases? Transport 5)Is the storing atmosphere free from excessive airborne dust? 6)Is the relay protected from oil and water splashes? 7)Is the relay subject to the application of heavy weight? 8)When shipping does vibration and impact exceed the allowable range?

ds_x61_en_relay_technical_information_091112D 21 Reliability RELIABILITY

[1] WHAT IS RELIABILITY? 1. Reliability in a Narrow Sense of the away or repair it. The reliability of 3. Intrinsic Reliability and Reliability Term repairable products is recognized as of Use In the industrial world, reliability is an “reliability in a broad sense of the term”. Reliability is “built” into products. This is index of how long a particular product For repairable products, their referred to as intrinsic reliability which serves without failure. serviceability or maintainability is another consists mainly of reliability in the narrow problem. In addition, reliability of product sense. 2. Reliability in a Broad Sense of the design is becoming a serious concern for Product reliability at the user’s site is Term the manufacturing industry. In short, called “reliability of use”, which consists Every product has a finite service lifetime. reliability has three senses: i.e. reliability mainly of reliability in the broad sense. In This means that no product can continue of the product itself, serviceability of the the relay industry, reliability of use has a normal service infinitely. When a product product, and reliability of product design. significance in aspects of servicing. has broken down, the user may throw it

1. Reliability (narrow sense), durability Long life time: MTTF, B10, R(T), Reliability Low failure rate: Lamda (λ), MTBF (broad sense) 2. Maintainability Availability MTTR Preventive maintenance, predicted maintenance 3. Design reliability Human factor, redundancy, fool-proof, fail-safe

[2] RELIABILITY MEASURES The following list contains some of the MTBF tells how long a product can be most popular reliability measures: used without the need for repair. Sample Reliability measure Sometimes MTBF is used to represent representation the service lifetime before failure. Degree of reliability R(T) 99.9% 10% MTBF 100 hours 3. MTTF MTTF 100 hours MTTF is an acronym of mean time to failure. It indicates the mean time period Failure rate  20 fit, 1%/hour B10 (c) Safe life until a product becomes faulty MTTF Safe life B10 50 hours normally applies to unrepairable products 1. Degree of Reliability such as parts and materials. Degree of reliability represents The relay is one of such objective of percentage ratio of reliability. For MTTF. f(t) example, if none of 10 light bulbs has failed for 100 hours, the degree of 4. Failure Rate reliability defined in, 100 hours of time is Failure rate includes mean failure rate 10/10 = 100%. If only three bulbs and momentary failure rate.

T Time remained alive, the degree of reliability is Mean failure rate is defined as follows: (a) R(T) 3/10 = 30%. Mean failure rate = Total failure count/ The JIS Z8115 standard defines the total operating hours degree of reliability as follows: MTTF In general, failure rate refers to The probability at which a system, momentary failure rate. This represents equipment, or part provides the specified the probability at which a system, functions over the intended duration equipment, or part, which has continued under the specified conditions. normal operation to a certain point of 2. MTBF time, becomes faulty in the subsequent specified time period. MTBF is an acronym of mean time Failure rate is often represented in the (b) MTTF between failures. It indicates the mean time period in which a system, unit of percent/hours. For parts with low –9 equipment, or part operates normally failure rates, “failure unit (Fit) = 10 / between two incidences of repair. MTBF hour” is often used instead of failure rate. only applies to repairable products. Percent/count is normally used for relays.

22 ds_x61_en_relay_technical_information_091112D Reliability 5. Safe Life 1 – R(B) = t % represents a more practical value of Safe life is an inverse of degree of In general, “B[1 – R(B)] = 10%” is more reliability than MTTF. reliability. It is given as value B which often used. In some cases this makes the following equation true:

[3] FAILURE 1. What is Failure? maintenance is effective for this type of Weibull distribution can be adopted to the Failure is defined as a state of system, failure. The timing of a relay’s wear-out actual failure rate distribution if the three equipment, or component in which part of failure can be predicted with a certain variables above are estimated. all of its functions are impaired or lost. accuracy from the past record of uses. The use of a relay is intended only in the 2. Bathtub Curve accidental failure period, and this period m Product’s failure rate throughout its virtually represents the service lifetime of lifetime is depicted as a bathtub curve, as the relay. Failure rate 63% shown below. Failure rate is high at the 3. Weibull Analysis beginning and end of its service lifetime. Weibull analysis is often used for (I) Initial failure period Time classifying a product’s failure patterns The high failure rate in the initial failure and to determine its lifetime. Weibull period is derived from latent design distribution is expressed by the following The Weibull probability chart is a simpler errors, process errors, and many other equation: causes. Initial failures are screened at alternative of complex calculation formulas. The chart provides the manufacturer’s site through burn-in m m m–1 process. This process is called f(x) = e – following advantages: debugging, performing aging or • The Weibull distribution has the closest screening. proximity to the actual lifetime m : Figure parameter (II) Accidental failure period distribution.  : Measurement parameter The initial failure period is followed by a • The Weibull probability chart is easy to long period with low, stable failure rate. In  : Position parameter use. this period, called accidental failure • Different types of failures can be period, failures occurs at random along identified on the chart. the time axis. While zero accidental The following describes the correlation failure rate is desirable, this is actually with the bathtub curve. The value of the not practical in the real world. figure parameter “m” represents the type (III) Wear-out failure period of the failure. In the final stage of the product’s service • When m < 1: Initial failures lifetime comes the wear-out failure • When m = 1: Accidental failures period, in which the life of the product • When m > 1: Wear-out failures expires due to wear of fatigue. Preventive

( I ) ( II ) ( III ) Failure rate

m > 1 m < 1 m = 1

Time

ds_x61_en_relay_technical_information_091112D 23 Applications of Relays in Electronic Circuits APPLICATIONS OF RELAYS IN ELECTRONIC CIRCUITS

[1] RELAY DRIVE BY MEANS OF A TRANSISTOR 1. Connection Method The voltage impressed on the relay is If the relay is transistor driven, we always full rated voltage, and in the OFF recommend using it with a collector time, the voltage is completely zero for connection. avoidance of trouble in use.

R Ry Tr Tr R1 Tr Ry

R2 Ry

(Good) Collector connection (Care) Emitter connection (Care) Parallel connection With this most common When the circumstances When the power consumed connection, operation is stable. make the use of this by the complete circuit connection unavoidable, if becomes large, consideration the voltage is not of the relay voltage is completely impressed on necessary. the relay, the transistor does not conduct completely and operation is uncertain.

2. Countermeasures for Surge the reverse blocking voltage should be somewhat higher than the supply Breakdown Voltage of Relay about 3 times the value of the power voltage. Control Transistor source voltage. If the coil current is suddenly interrupted, Connection of a diode is an excellent way a sudden high voltage pulse is developed to prevent voltage surges, but there will Diode in the coil. If this voltage exceeds the be a considerable time delay when the Ry breakdown voltage of the transistor, the relay is open. If you need to reduce this transistor will be degraded, and this will time delay you can connect between the lead to damage. It is absolutely transistor’s collector and emitter a Zener necessary to connect a diode in the diode that will make the Zener voltage Tr circuit as a means of preventing damage from the counter emf. As suitable ratings for this diode, the current should be equivalent to the Take care of the “Area of Safe Operation (ASO)” average rectified current to the coil, and

3. Snap Action Unlike the characteristic when voltage is the rated voltage in a short time and also (Characteristic of relay with voltage rise impressed slowly on the relay coil, this is to drop the voltage in a short time. and fall of voltage) the case where it is necessary to impress

Non-pulse signal Pulse signal (square wave)

IB Ry

Tr Ic IC IB

ON Ry OFF (No Good) Without snap action (Good) Snap action)

4. Schmidt Circuit (Snap Action When the input signal does not produce a Characteristic points

Circuit) snap action, ordinarily a Schmidt circuit is • The common emitter resistor RE must (Wave rectifying circuit) used to produce safe snap action. have a value sufficiently small

24 ds_x61_en_relay_technical_information_091112D Applications of Relays in Electronic Circuits compared with the resistance of the Schmidt trigger circuit. (However, the relay coil. response speed drops.) • Due to the relay coil current, the difference in the voltage at point P

when Tr2 is conducting and at point P R1 Ry when Tr1 is conducting creates hysteresis in the detection capability of Signal R3 R2 Schmidt circuit, and care must be taken Tr1 Tr2

in setting the values. P • When there is chattering in the input signal because of waveform oscillation, RE an CR time constant circuit should be inserted in the stage before the

5. Avoid Darlington Connections. technology. This does not mean that it is (High amplification) immediately connected to the defect, but it is linked to troubles that occur after long This circuit is a trap into which it is easy periods of use and with many units in to fall when dealing with high circuit operation.

Ry Ry

Tr1 Tr1 V CESAT = Tr2 V CESAT = About 0.7V Tr2 About 0.1V

GND

(No good) Darlington connection (Good) Emitter connection (Due to excessive consumption of power, heat (Tr2 conducts completely.) is generated.) (Tr1 is sufficient for signal use.) (A strong Tr1 is necessary)

6. Residual Coil Voltage Connection to the next stage through In switching applications where a collector semiconductor (transistor, UJT, etc.) is connected to the coil, a residual voltage is retained at the relay coil which may Ry cause incomplete restoration and faulty IO operation. By using DC coils, there may be a reduction in; the danger of T1 T2 incomplete restoration, the contact pressure, and the vibration resistance. This is because the drop-out voltage is 10% or more of the rated voltage, a low IO: dark current (No good) value compared to that for AC coil, and also there is a tendency to increase the life by lowering the drop-out voltage. When the signal from the transistor’s collector is taken and used to drive another circuit as shown in the figure on the right, a minute dark current flows to the relay even if the transistor is off. This may cause the problems described above.

ds_x61_en_relay_technical_information_091112D 25 Applications of Relays in Electronic Circuits [2] RELAY DRIVE BY MEANS OF SCR 1. Ordinary Drive Method 2. Caution points regarding ON/OFF • When the load for the temperature For SCR drive, it is necessary to take control circuits control is a high current load such as a particular care with regard to gate (When used for temperature or similar heater, the switching can occur only at sensitivity and erroneous operation due control circuits) peak values and it can occur only at zero phase values as a phenomenon of to noise. When the relay contacts close this type of control. (Depending upon simultaneously with an AC single phase the sensitivity and response speed of power source, because the electrical life the relay) Ry R of the contacts suffers extreme shortening, care is necessary. • Accordingly, either an extremely long life or an extremely short life results S • When the relay is turned ON and OFF with wide variation, and it is necessary IGT C using a SCR, the SCR serves as a half to take care with the initial device wave power source as it is, and there quality check. are ample cases where the SCR is RGK easily restored. There is no problem even with more then 3 times IGT : Ry the related current. • In this manner the relay operation and

RGK : 1K Ω must be connected. restoration timing are easily R,C : This is for prevention of ignition error due to a synchronized with the power source sudden rise in the power source or to noise. Ry (dv/dt countermeasure) frequency, and the timing of the load S switching also is easily synchronized. Heater

[3] RELAY DRIVE FROM EXTERNAL CONTACTS Relays for PC board use have high When the frequency of use is low, with sensitivity and high speed response the delay in response time caused by a characteristics, and because they condenser, it is possible to absorb the External contact respond sufficiently to chattering and chattering and bouncing. bouncing, it is necessary to take care in (However, it is not possible to use only a their drive. condenser. A resistor should also be Ry R used with the capacitor.) C

[4] LED SERIES AND PARALLEL CONNECTIONS

1) In series with relay 2) R in parallel with LED 3) In parallel connection with relay

R2 Ry Ry

Ry

LED R1

Power consuption: Power consuption: Power consumption: In common with relay (Good) Current limiting resistor R2 (Care) Defective LED: In common with relay (Good) Defective LED: Relay does not operate (No Good) Defective LED: Low voltage circuit: Relay operate (Good) Relay operate stable (Good) With LED, 1.5V down (No good) Low voltage circuit: (Good) No. of parts: (Good) Low voltage cicuit: No. of parts: R2 (Care) With LED, 1.5V down (No good) No. of parts: R1 (Care)

26 ds_x61_en_relay_technical_information_091112D Applications of Relays in Electronic Circuits [5] ELECTRONIC CIRCUIT DRIVE BY MEANS OF A RELAY 1. Chatterless Electronic Circuit Even though a chatterless characteristic is Notes: 1. The A, B, and C lines should be made as short as possible. 2. it is necessary that there be no noise from the coil section included into the contact section a feature of relays, this is to the fullest A extent a chatterless electrical circuit, much Ry the same as a mercury relay. To meet the requirement for such circuits as the input to a binary counter, there is an electronic N.O. chatterless method in which chattering is absolutely not permissible. Even if N.C. chattering develops on one side, either the N.O. side contacts or the N.C. side Binary contacts, the flip flop does not reverse, and C B counter the counter circuit can be fed pulsed R-S-F.F without a miss. (However, bouncing from the N.O. side to N.C. side must be absolutely avoided.) 2. Triac Drive When an electronic circuit using a direct drive from a triac, the electronic circuit will not be isolated from the power circuit, and because of this, troubles due to erroneous operation and damage can develop easily. L The introduction of a relay drive is the most economical and most effective solution. Ry (Photo coupler and pulse transformer circuits are complicated.) Also, compared to switching a direct load with a relay, long life and reduced arc noise can be achieved. When a zero cross switching characteristic is necessary, a solid state relay (SSR) should be used.

[6] POWER SOURCE CIRCUIT 1. Constant Voltage Circuit In general, electronic circuits are extremely vulnerable to such phenomena as power Ry supply ripples and voltage fluctuations. C Although relay power supplies are not as vulnerable as electronic circuits, please keep both ripples and the regulation within the specification. Stabilized circuit (Example) Figure 17 If power supply voltage fluctuations are large, please connect a stabilized circuit or constant-voltage circuit as shown in Figure Relay power supply 17. Stabilized or constant-voltage power supply If the relay power consumption is great, C Electronic circuit satisfactory results can be achieved by supply implementing a circuit configuration as Stabilized power shown in Figure 18. Figure 18

ds_x61_en_relay_technical_information_091112D 27 Applications of Relays in Electronic Circuits

2. Prevention of Voltage Drop Due to Rush Current

In the circuit shown in Figure 19, rush Ry current flows from the lamp or capacitor. The instant the contacts close, the voltage C drops and the relay releases or chatters. In this case it is necessary to raise the Lamp transformer's capacity or add a smoothing circuit. Figure 20 shows an example of the Figure 19 modified circuit. Figure 21 shows a battery-powered version. Ry

C

C Lamp

Figure 20

Ry

Battery M Motor C

Figure 21

[7] PC BOARD DESIGN CONSIDERATIONS 1. Pattern Layout for Relays Since relays affect electronic circuits by Avoid routing pattern traces susceptible broken seal. Even for the same circuit, generating noise, the following points to noise (such as for audio signals) pattern design considerations which should be noted. underneath the relay coil section. Avoid minimize the influence of the on/off Keep relays away from semiconductor through-holes in places which cannot be operations of the relay coil and lamp on devices. Design the pattern traces for seen from the top (e.g. at the base of the other electronic circuits are necessary. shortest lengths. Place the surge relay). Solder flowing up through such a absorber (diode, etc.) near the relay coil. hole may cause damage such as a

Relay coil Ry Ry (No good) A Good A2

CO A1 Co Diode bridge

Diode bridge B1 Constant B Constant Tr voltage Electronic Electronic voltage circuit circuit B2 Tr Relay coil currents and electronic circuit Relay coil currents consist only of A1 and B1. flow together trough A and B. Electronic circuit currents consist only of A2 and B2. A simple design consideration can change the safety of the operation.

2. Hole and land diameter The hole diameter and land are made with the hole slightly larger than the lead wire so that the component may be inserted easily. Also, when soldering, the solder will build up in an eyelet condition, increasing the mounting strength.

28 ds_x61_en_relay_technical_information_091112D Applications of Relays in Electronic Circuits The standard dimensions for the hole diameter and land are shown in the table.

Standard dimensions for hole and land diameter mm inch Standard hole diameter Tolerance Land diameter 0.8 .031 2.0 to 3.0 .079 to .118 1.0 .039 0.1 ±.039 1.2 .047 3.5 to 4.5 .138 to .177 1.6 .063 Remarks 1. The hole diameter is made 0.2 to 0.5mm .008 to .020inch larger than the lead diameter. However, if the jet method (wave type, jet type) of soldering is used, because of the fear of solder passing through to the component side, it is more suitable to make the hole diameter equal to the lead diameter +0.2mm. 2. The land diameter should be 2 to 3 times the hole diameter. 3. Do not put more than 1 lead in one hole.

3. Expansion and shrinkage of copperclad laminates Because copperclad laminates have a made with the connector along the longitudinal and lateral direction, the longitudinal side. manner of punching fabrication and layout must be observed with care. The Example: As shown is the drawing below, the 150mm 5.906 inch direction is taken as the longitudinal expansion and shrinkage in the direction longitudinal direction due to heat is 1/15 Direction to 1/2 that in the lateral, and accordingly, 150 5.906 after the punching fabrication, the distortion in the longitudinal direction will 70 Longitudinal be 1/15 to 1/2 that of the lateral direction. 2.756 direction The mechanical strength in the longitudinal direction is 10 to 15% greater Also, as shown in the drawing below, when the pattern than that in the lateral direction. Because has a connector section, the direction is taken as of this difference between the longitudinal shown by the arrow in the longitudinal direction and lateral directions, when products having long configurations are to be fabricated, the lengthwise direction of the configuration should be made in the Longitudinal longitudinal direction, and PC boards direction having a connector section should be

4. When it is necessary to use hand soldering for one part of a component after dip soldering has been done By providing a narrow slot in the circular part of the foil pattern, the slot will prevent the hole from being plugged with solder.

0.3 to 0.5mm .012 to 020 inch

5. When the PC board itself is used as a connector • The edge should be beveled. (This • When only a single side is used as the • Care should be taken. prevents peeling of the foil when the connector blade, if there is distortion in board is inserted into its socket.) the PC board, contact will be defective.

Through hole

Bevel of radius (Care) (Good) (Good) Contact on both surfaces

ds_x61_en_relay_technical_information_091112D 29 Applications of Relays in Electronic Circuits 6. PC Board Reference Data This data has been derived from samples the thinner the copper foil, the larger the relationship between the current and the of this company’s products. Use this data temperature rise.) For example, too high conductor width for each rise in as a reference when designing PC a rise in temperature causes degradation temperature for different copper foils. It is boards. of the characteristic and color changes of also necessary to give consideration to • Conductor width the laminate. In general, the allowable preventing abnormal currents from current of the conductor is determined so exceeding the destruction current of the The allowable current for the conductor that the rise is temperature is less than conductor. was determined from the safety aspect 10C. It is necessary to design the Figure 25 shows the relationship and the effect on the performance of the conductor width from this allowable between the conductor width and the conductor due to the rise in saturation conductor current. destruction current. temperature when current is flowing. Figure 22, Figure 23, Figure 24 show the (The narrower the conductor width and

10 10 14 Copper foil Copper foil Copper foil .035mm 60°C 140°F 13 9 .018mm 9 .070mm 60°C 140°F .0007 inch .001 inch 12 .003 inch 8 8 11 40°C 104°F 40°C 104°F 7 7 10 60°C 140°F 6 9 6 8 20°C 68°F 20°C 68°F 5 40°C 104°F 5 7

Current, A 6 4 Current, A 4 10°C 50°F 20°C 68°F Current, A 5 10°C 50°F 3 3 4 10°C 50°F 2 2 3 1 2 1 1 0 0 0 0.2 0.5 1.0 1.5 2.5 3.0 0 0 0.2 0.5 1.0 1.5 2.0 2.5 3.0 2.0 0 0.5 1.0 1.5 2.0 2.5 3.0 0 .008 .020 .039 .059 .079 .098 .118 0.008.020 .039 .059 .079 .098 .118 0 .020 .039 .059 .079 .098 .118 Conductor width, mm inch Conductor width, mm inch Conductor width, mm inch

Figure 22 Figure 23 Figure 24 Copper foil thick 40 .070 Copper foil width = 0.5 .020 .003 200 35 .035mm 1.0 .039 100 .001 inch 30 .035 50 2.0 .079 .001 25 Ω 30 3.0 .118 20 20 .018 10 .0007 15 5 Resistance, m Destruction current, A Destruction current, 3 10 2 5 1 0 0 0.5 1.0 1.5 2.0 2.5 3.0 0.5 1 2 3 5 10 20 30 50 100 200 0 .020 .039 .059 .079 .098 .118 .197 .394 .787 1.181 1.969 3.937 7.874 11.811 19.685 39.37 78.74 Conductor width, mm inch Conductor length, cm inch

Figure 25 Figure 26 • Space between conductors standards, it is necessary to conform to Example of conductor spacing design Figure 27 shows the relationship between the regulations. Maximum DC and Minimum Conductor the spacing between conductors and the 6.0 AC Voltage Between Spacing (mm inch) destruction voltage. This destruction Conductors (V) voltage is not the destruction voltage of 5.0 0 to 50 0.381 .015 the PC board; it is the flash over voltage 51 to 150 0.635 .025 4.0 (insulation breakdown voltage of the 151 to 300 1.27 .050 space between circuits.) Coating the 3.0 301 to 500 2.54 .100 surface of the conductor with an insulating Calculated at 500 or more resin such as a solder resist increases the 2.0 0.00508 mm/V flash over voltage, but because of the pin holes of the solder resist, it is necessary to (kV) Destruction Voltage 1.0 consider the conductor destruction 0 voltage without the solder resist. In fact, it 0 0.2 0.5 1.0 2.0 3.0 4.0 0 .008 .020 .039 .079 .118 .157 is necessary to add an ample safety factor Conductor width mm inch when determining the spacing between Figure 27 conductors. Table shows an example of a design for the spacing between conductors. (Taken from the JIS C5010 standards.) However, when the product is covered by the electrical products control law, UL standards or other safety

30 ds_x61_en_relay_technical_information_091112D Relay Soldering and Cleaning Guidelines RELAY SOLDERING AND CLEANING GUIDELINES

In keeping with making devices compact, of seepage into the relay of flux, which is The type of protective structure will it is becoming more common to weld the applied to the PC board. Therefore, the determine suitability for automatic relay to a PC board along with the following precautions are provided for soldering or automatic cleaning. Please semiconductors instead of using the soldering a relay onto a PC board. review the parts on construction and previous plug-in type in which relays Please refer to them during installation in characteristics. See “Configuration and were plugged into sockets. With this order to avoid problems. Construction” on page 1. style, loss of function may occur because

1. Mounting of relay performance cannot be guaranteed if don’t rattle.) Interference may occur the terminals are bent. Self-clinching internally if the gripping force of the tab terminal types are available depending of the surface mounting machine is too on the type of relay. great. This could impair relay • Correctly drill the PC board according performance. to the given PC board pattern illustration. • Stick packaging is also available for automatic mounting, depending on the • Avoid bending the terminals to make type of relay. (Be sure that the relays the relay self-clinching. Relay Bad example

2. Flux application • Adjust the position of the PC board so pressed down hard enough, flux may that flux does not overflow onto the top even penetrate a flux-resistant type of it. This must be observed especially relay. for dust-cover type relays. • Use rosin-based non-corrosive flux. • If the PC board is pressed down into a flux-soaked sponge as shown on the right, the flux can easily penetrate a dust-cover type relay. Never use this method. Note that if the PC board is Bad example

3. Preheating • Be sure to preheat before using • Preheat according to the following automatic soldering. For dust-cover conditions. type relays and flux-resistant type Temperature 120C 248F or less relays, preheating acts to prevent the Time Within approx. 2 minutes penetration of flux into the relay when • Note that long exposure to high soldering. Solderability also improves. temperatures (e.g. due to a malfunctioning unit) may affect relay characteristics.

4. Soldering • Automatic soldering degrade due to the high thermal • Flow solder is the optimum method for capacity of these boards. soldering. • Hand soldering • Adjust the level of solder so that it does Keep the tip of the soldering iron clean. not overflow onto the top of the PC Soldering Iron 30W to 60W board. Iron Tip 350C 662F • Unless otherwise specified, solder Temperature under the following conditions Soldering Time Within approx. 3 seconds depending on the type of relay. Solder 260C5C 500F41F temperature Soldering time Within approx. 6 seconds • Please take caution with multi-layer boards. Relay performance may ds_x61_en_relay_technical_information_091112D 31 Relay Soldering and Cleaning Guidelines 5. Cooling • Automatic soldering • Hand soldering • Immediate air cooling is recommend to — prevent deterioration of the relay and surrounding parts due of soldering heat. • Although the environmentally sealed type relay (plastic sealed type, etc.) can be cleaned, avoid immersing the relay into cold liquid (such as cleaning solvent) immediately after soldering. Doing so may deteriorate the sealing performance.

6. Cleaning • Do not clean dust-cover type relays chloroethene, thinner, benzyl alcohol, and flux-resistant type relays by gasoline) may damage the relay case. immersion. Even if only the bottom • Cleaning with the boiling method is surface of the PC board is cleaned recommended. Avoid ultrasonic (e.g. with a brush), careless cleaning cleaning on relays. Use of ultrasonic may cause cleaning solvent to cleaning may cause breaks in the coil penetrate the relay. or slight sticking of the contacts due to • Plastic sealed type relays can be the ultrasonic energy. cleaned by immersion. Use a Freon- or • Do not cut the terminals. When alcohol-based cleaning solvent. Use of terminals are cut, breaking of coil wire other cleaning solvents (e.g. Trichlene, and slight sticking of the contacts may occur due to vibration of the cutter.

7. Coating • If the PC board is to be coated to coating material. The solder may peel prevent the insulation of the PC board off from thermal stress. from deteriorating due to corrosive • Depending on the type, some coating gases and high temperatures, note the materials may have an adverse affect following. on relays. Furthermore, solvents (e.g. • Do not coat dust-cover type relays and xylene, toluene, MEK, I.P.A.) may flux-resistant type relays, since the damage the case or chemically coating material may penetrate the dissolve the epoxy and break the seal. relay and cause contact failure. Or, Select coating materials carefully. mount the relay after coating. • If the relay and all components (e.g. • If the relay and all components (e.g. ICs) are to be coated, be sure to ICs) are to be coated, be sure to carefully check the flexibility of the carefully check the flexibility of the coating material. The solder may peel off from thermal stress. Suitability Type Features for Relays • Good electrical insulation. Epoxy-base Good • Although slightly difficult to apply, does not affect relay contacts. • Good electrical insulation, easy to apply. Urethane-base Care • Solvent may damage case. Check before use. • Silicone gas becomes the cause of contact failure. Silicone-base No Good Do not use the silicone-base type.

32 ds_x61_en_relay_technical_information_091112D SMT Soldering Guidelines SMT SOLDERING GUIDELINES CAUTIONS FOR SURFACE MOUNT RELAY INSTALLATION To meet the market demand for surface mounting technology. To meet mount relay installation to prevent downsizing to smaller, lighter, and thinner this need, we offer a line of surface malfunction and incorrect operation. products, PC boards also need to mount relays. The following describes proceed from Insertion mounting to some cautions required for surface

[1] What is a Surface Mount Relay? 1. From IMT to SMT high heat stresses from reflow soldering We applied the experience gained from Conventional insertion mount technology because they use no mechanical parts. In our advanced relay technologies to (IMT) with some 30 years of history is contrast, the conventional electro- produce high-performance now being replaced with surface mount mechanical relays consisting of solenoid electromagnetic relays compatible with technology (SMT). coils, springs, and armatures are very surface mount technologies such as IRS sensitive to thermal stress from reflow and VPS. Solid-state components such as soldering. resistors, ICs, and diodes can withstand •Insertion Mount Technology (IMT) vs. Surface Mount Technology (SMT)

Components’ leads are inserted into Relay Resistor lead holes drilled into the PC board Insertion Mounting and are soldered to copper pads on Technology (IMT) the other side of the board using PC board flow-soldering techniques.

Components are placed on copper Relay Clip resistance pads precoated with paste solder Surface Mount Technology and the board assembly is heated to (SMT) PC board solder the components on the pads IC (reflow soldering).

2. Features and Effects Features Effects The surface mount relay is manufactured with • Allows high density mounting the following advanced technologies: • Components can be installed on both sides of a board System downsizing • Ceramic PC boards can be used • Heat-resistance encapsulation technique • Compatible with automatic placement by robots • Gas analysis • Drilling for lead holes is not required Overall cost reduction • Reliability assessment • Compact system designs are possible due to high density mounting • High heat resistance • Precision molding technique for heat- High reliability • Anti-gas measures resistant materials

3. Examples of SMT Applications The following describes some examples With VPS technology, PCB assemblies • Double Wave Soldering (DWS) of typical SMT applications: are carried through a special inactive Components are glued to the PC board • Infrared Reflow Soldering (IRS) solvent, such as Fluorinert FC-70, that surface. The board assembly is has been heated to a vapor state. As the IRS is the most popular reflow soldering transferred through a molten solder saturated vapor condenses on the PC technology now available for surface fountain (with the component side facing board surface, the resulting evaporation mounting. It uses a sheath heater or down), and the components are soldered heat provides the energy for reflow infrared lamp as its heat source. PC to the board. soldering. board assemblies are continuously • Other Technologies soldered as they are transferred through Other reflow soldering technologies a tunnel furnace comprised of a Cooling oil include those utilizing lasers, hot air, and preheating, heating, and cooling-stages. pulse heaters. Saturated vapor

Preheat Heating Cooling stage stage stage Heater

• Belt conveyer reflow furnace As PCB assemblies are transferred on a thin, heat-resistant belt conveyer, they • Vapor Phase Soldering (VPS) are soldered by the heat from hotplates placed begeath the conveyer belt. ds_x61_en_relay_technical_information_091112D 33 SMT Soldering Guidelines [2] Cautions for installation • • Mounting pads on PC boards must be 1. Paste Soldering designed to absorb placement errors Screen Printing while taking account of solderability Squeegee Paste solder and insulation. Refer to the suggested (for screen printing) mounting pad layout in the application Mask Pad data for the required relay product. • Paste solder may be applied on the PC board board with screen printing or dispenser Solder Dispenser techniques. For either method, the Air paste solder must be coated to Syringe appropriate thickness and shapes to Paste solder (for dispenser) achieve good solder wetting and Needle adequate insulation. Pad PC board

• For small, lightweight components • Our SMT relays are supplied in stick 2. Relay Installation such as chip components, a self- packaging compatible with automatic alignment effect can be expected if placement processes. We also offer small placement errors exist. However, tape packaging at customer request. this effect is not as expected for Holding Pressure electro-mechanical components such Direction A: Less than 9.8 N (less than 1,000 gf) Direction B: Less than 9.8 N (less than 1,000 gf) as relays, and they require precise Direction C: Less than 9.8 N (less than 1,000 gf) C positioning on their soldering pads. A B • If SMT relays sustain excessive mechanical stress from the placement machine’s pickup head, their performance cannot be guaranteed. (ex. TQ-SMD Relay)

• IRS technique • Manual soldering 3. Reflow T3 - Soldering iron tip temperature: 350C 662°F T2

T1 - Soldering iron wattage: 30 to 60 watts - Soldering time: Less than 3 sec. t1 t2 T1 = 150 to 180°C 302 to 356°F t1 = 60 to 120 sec. • Others T2 = 230°C 446°F or more t2 = Less than 30 sec. T3 = Less than 250°C 482°F When a soldering technique other than above is to be used (hot air, hotplate, Note laser, or pulse heater technique), Reflow soldering under inadequate carefully investigate the suitability of soldering conditions may result in the technique. - It is recommended that the soldered unreliable relay performance or even pad be immediately cooled to Notes: physical damage to the relay (even if the prevent thermal damage to the relay relay is of surface mount type with high • The soldering temperature profile and its associated components. heat resistance). indicates the pad temperature. In some - While surface mount relays are cases, the ambient temperature may Example of Recommended Soldering solvent washable, do not immerse be greatly increased. Check for the Condition for Surface Mount Relays. the relay in cold cleaning solvent specific mounting condition. immediately after soldering. • Please use promptly once the anti- humidity pack is opened (Signal relay: with in 3 days, Max. 30C 86°F/ 60%RH). If left with the pack open, the relay will absorb moisture which will cause thermal stress when reflow mounting and thus cause the case to expand. As a result, the seal may break.

34 ds_x61_en_relay_technical_information_091112D SMT Soldering Guidelines • The surface mount relays are solvent 4. Cleaning washable. Use alcohol or an equivalent solvent for cleaning. • Boiled cleaning is approved for surface mount relays. Ultrasonic cleaning may cause coil damage or light contact sticking.

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