Dehumidifier Control/Alarm System

HYGRODYNAMICS

DEHUMIDIFIER CONTROL/ALARM SYSTEM

MODEL NO. 3262 9332 9333

CONTENTS

I. General Description 1 II. Specifications 3 III. Installation 4 IV. Operation 10 V. Maintenance 11 VI. Parts List 13 WARRANTY 19

ILLUSTRATIONS

1. Typical Units of the 9332 D/H Control/Alarm System 1 2. Mounting Dimensions 4 3. System Wiring Connection 7 4. Terminal Identification, 9333 Central Alarm Unit 8 5. Terminal Identification, 3262 Station Control Unit 8 6. Overall Dimensions, 9333 Alarm Unit 14 7. Overall Dimensions, 3262 Station Unit 15 8. Internal Wiring Connections, 9333 Alarm Unit 16 9. Internal Wiring Connections, 3262 Station Unit 17 10. Circuit Diagram, 9332 D/H Alarm System 18

NEWPORT SCIENTIFIC, INC. 8246-E SANDY COURT JESSUP, MD 20794 TEL: (301) 498-6700 FAX: (301) 490-2313 DECEMBER 1990 H:\ADMIN\MANUAL\9332 Central Visual Alarm Unit Station Control Unit

Figure 1. Typical Units of the 9332 Dehumidifier Control/Alarm System

I. GENERAL DESCRIPTION

A. System Components

1. The HYGRODYNAMICS Dehumidifier Control/Alarm System consists of a central visual alarm unit; four remote, dual-sensor station control units—each with a variable % R.H. control—and a separate control relay for the Dehumidifier unit. The station control units are mounted at four remote locations and are connected to the central alarm unit with electrical cables.

2. Central Visual Alarm Unit. The central alarm unit is housed in a sturdy metal, NEMA Type 4, weather tight box primed with zinc chromate and finished with yellow enamel. The box is designed for vertical mounting. The cover/panel has four red indicator lamps, one for each station, a LOW RH test pushbutton, a lamp TEST pushbutton, and a fuse holder. Power connection terminals and station terminal strips are inside the box.

3. Station Control Unit. Each of the four dual sensor station units is housed in a sturdy metal case primed with zinc chromate and finished with good quality yellow enamel. An adjustable knob mounted on the cover indicates the control point between 28% and 42% R.H. Two plug-in humidity sensors are externally mounted on the bottom panel. Each station unit contains two solid-state printed circuits, one for the control signal, the other for the high and low signals that are transmitted to the central visual alarm by the interconnecting cables. 1 4. Sensors. The humidity sensor used in this system is the Hygrodynamics HYGROSENSOR, a Dunmore-type lithium chloride resistance transducer, the resistance of which changes instantly with the relative humidity to which it is exposed. The sensing element is a bifilar winding of noble metal on a cylindrical coil form protected by a cylindrical, non-ferrous, perforated metal jacket. The polystyrene sensor base is fitted with two plug-in connector pins.

5. Relay. A power relay, supplied with the system, is activated by the controller circuit relays in the sensor station units. The power relay in turn activates the dehumidifier unit.

B. Purpose

1. This system is designed to control continuously and automatically the relative humidity within a controlled space or enclosure at a preset level and to provide a visual alarm at a central location if the relative humidity falls below, or rises above the preset value.

2. The four remote sensor stations activate a common dehumidifier when humidity at any of the four locations rises above the preset value and deactivate it is the humidity falls below the preset value at any of the four stations. Thus the system prevents either excessive humidity which can cause damage, or unnecessary drying within the controlled space.

3. Each indicator lamp on the central alarm panel identifies the remote station at which the humidity has varied from the preset value, whatever the reason.

C. Theory of Operation

1. Operation of the Hygrosensor, the humidity transducer used in the system is based on the ability of a hygroscopic film to change its electrical resistance instantly with microchanges in the relative humidity to which it is exposed.

2. An excitation voltage is applied to the sensor and the change in resistance is relayed to a measuring circuit.

3. In this dual-sensor control/alarm system, one sensor and its circuit provides control with high alarm (activated when the R.H. is 5% above the control value): the second sensor and its circuit provides a low (25%) R.H. monitoring signal.

4. The system is fail-safe to the extent that, if the power fails or is turned off at a remote station, but remains on at the central alarm unit, the alarm indicator will be energized. Also, if the power remains on, the dryer relay and the dryer will continue to operate until controller operation is restored.

2 II. SPECIFICATIONS

Control Range Adjustable between 28% and 40% R.H.

Graduated Scale 28% to 42% R.H.

System Stability +2% R.H. at 80F (26.7C) between 20% and 40% R.H.

Sensor Temperature Coefficient 0.15% R.H. per degree F.

High R. H. Alarm Point* Preset for alarm at 5% R. H. above control setting

Low R.H. Monitoring Manual push-button check, indicates alarm when R.H. falls below 25%

Power Requirement 115V, 60 Hz for each unit

Power Relay Rating 115VAC coil, SPST, 16 amperes N/O (Separate unit) 115VAC contacts

Size Overall:

Central Alarm Unit 29 x 22.5 x 13.5 cm deep (11.5 x 9 x 5.25 inches deep)

Station Unit 23 x 16 x 12 cm deep (incl. sensor) (8.2 x 6.2 x 4.27 inches deep)

Relay 3 x 6.5 x 4 cm deep (1-1/4 x 2-1/2 x 1-5/8 inches deep)

Weight:

Central Alarm Unit 11-1/4 lbs. net; 13 lbs. shipping Station Unit 5-1/2 lbs. net; 7 lbs. shipping Relay 3 oz. Net; ½ lb. Shipping

Finish Bright yellow enamel Primed with zinc chromate

*Control may be set around 40% R.H. but high alarm will be ineffective at these settings.

3 III. INSTALLATION

The Control/Alarm System consists of :

1 – 9333 Central Alarm Unit

4 – 3262 Station Unit, each with:

2 – 4817 Hygrosensor, orange band

1 – 0400102 Capacitor, .047uf, 600 VDC

1 – 3400603 Power Relay, 115 VAC, SPST

Power cables and switches for 115V service, and unit interconnecting cables are supplied by user.

Central Alarm Unit Station Control Unit Figure 2. Mounting Dimensions

A. Central Alarm Panel Unit

1. Position this unit at a convenient location where it can be observed and checked by inspecting personnel. 2. The Central Alarm Panel Unit is designed for vertical mounting. It should be mounted on a surface free of severe vibration or shock. If located outdoors, use weatherproof electrical conduit and fittings.

4 B. Station Control Units

1. Position these units in areas representative of the entire space to be monitored. The units should be mounted on an interior wall or bulkhead that is relatively free from severe vibration. Avoid locations directly in front of ducts, areas subject to radiant heat from heaters, lamps or direct sunlight, and cold walls subject to condensation.

2. These units are also designed for vertical mounting on a wall or bulkhead. Mounting holes are located on the back panel and access to them is obtained by opening the front cover. See Figure 2 for mounting dimensions.

C. Power Relay

1. Mount the power relay with the 0.047 uf capacitor in, or adjacent to the dehumidifier unit.

2. The relay requires a space 1-1/4” wide x 2-1/2” high x 1-5/8” deep and two mounting holes on bracket are 2-1/8” centers.

D. Connections

1. Interconnecting cables and power switches for each unit are supplied by the user. Use #18 AWG or larger 3-conductor cable for connections between units. Use approved power switches and grounded 3-conductor power line wire in accordance with national and local electrical codes.

2. Central Alarm Unit Panel. Refer to Figures 3 and 4.

a. Loosen the four screws securing the cover and carefully open the cover. b. Drill a hole at the bottom or right side of the box, next to the terminal strip of the appropriate size to accept weatherproof conduit. c. Run the power line cable through the conduit and connect it to the terminals labeled HOT, NEUTRAL, and GROUND respectively. d. Drill other holes to accept the conduit lines from the four stations at the bottom or left side of the box. Connect each station to terminals 1, 2, and 3 as specified on the 12-terminal strip. Refer to Figures 3 and 4.

5 3. Station Control Unit, See Figures 3 and 5.

a. Connect the 3-conductor cables from the station terminals of the Central Alarm Unit to the terminals marked 3, 2, and 1 on TB-1 of each sensor station unit. See Figures 5 and 9.

b. Connect the power line to terminals marked HOT, NEUTRAL, and GROUND as shown in Figures 5 and 9.

c. Connect a 2-conductor wire from the terminals marked D/H CONTROL RELAY to power and to the power relay which activates the dehumidifier.

d. Connections between the two terminal strips in the station units should not be disturbed.

4. Power Relay

a. Connect the 2-conductor cable from terminals marked D/H CONTROL RELAY from each station to the power input line of the relay as shown in Figure 3.

b. Connect the control relay output line to the humidifier, as shown in Figure 3.

c. Connect the 0.047 uf capacitor between the HOT and NEUTRAL input lines to the relay.

5. Connect all connections for compliance with the system wiring diagram, Figure 3 and the schematic diagram Figure 10.

E. System Check. After Installation or Subsequent Reactivation.

Do not install sensor until after the system check has been completed. If sensors have been previously installed, insert a small screwdriver through the center hole at the end of the sensor jacket and remove the small screw securing the sensor to its socket. Unplug the sensors and store them temporarily where they will not be contaminated.

CAUTION

Do not expose sensors to contaminated atmospheres, such as dust, smoke, chemical fumes, water spray, fog, steam or other conditions likely to cause condensation on the sensor. To do so will damage the sensor and will void all warranties.

6 1. Apply AC power to the system. Allow a few minutes warm-up.

2. Set each station unit to 34% R.H. The D/H unit should not be operating.

3. Push the TEST switch on the central alarm panel unit. All four pilot lights should light.

4. Push the LOW R.H. switch on the central alarm panel unit. All four lights should light.

5. If the unit does not respond in steps 3 or 4, check all wiring and repeat test. Check troubleshooting section, if necessary. When proper response is obtained, proceed with step 6.

6. Turn AC power OFF on Station 1. Using short lengths of bus wire (or paperclips), short circuit the two terminals farthest apart in each sensor socket on Station unit 1.

CAUTION

Always turn power OFF while making bare-wire connections in sensor socket. DO NOT HANDLE EXPOSED BUS WIRE WHEN CONDUCTING TESTS WITH POWER ON.

Turn power ON and allow warmup time. The D/H machine should operate and the alarm light for Station 1 should turn ON. Turn power OFF. Remove shorts and re- energize.

7. Repeat this test for stations 2, 3, and 4. In each case, the D/H unit should operate and the alarm for the corresponding station should light.

F. Sensor Installation

1. When proper response to the tests in step E is obtained, plug the ORANGE-banded Hygrosensors, 4817, into the left sensor receptacles of the station units and secure them with the small screws supplied. These are the CONTROL and HIGH R.H. alarm sensors.

2. Plug a second ORANGE-banded Hygrosensor into the sensor receptacles at the right of the station units and secure them with the small screw supplied. These are the LOW R.H. alarm sensors.

3. When sensors are installed at all four stations, the system is ready for operation.

9 IV. OPERATION

A. Alarm Setting

1. Set the % R.H. control on each station control unit at the middle of the dial, (between 33% and 34%). Other settings, up to 40% R.H., may be used, based on system air distribution and other requirements, and, different settings may be used on different station units in the same system.

2. Apply power to the four station control units, the Central Alarm Panel and the Dehumidifier Unit. If conditions at any of the stations call for dehumidification, the dehumidifier unit will operate.

3. Allow sufficient time for the space being monitored and controlled to reach equilibrium, at which time the high alarm indicators will go OFF. The condition should now be maintained automatically. If any station alarm light fails to go OFF, check for presence of water or leaks in the barrier material of the enclosure.

B. Balancing

1. Effectiveness of humidity control depends on the respective size of the areas being monitored, exposure to the sun, temperature differences between stations and the station distance from the dehumidifier unit, all of which may require adjustments in the air distribution system to achieve balance throughout the four areas served by the common dehumidifier.

2. Ideal operation of the system is indicated by fairly regular ON and OFF cycling of the dehumidifier and the absence of HIGH or LOW alarms in any of the four areas being monitored.

3. If HIGH alarm is indicated at any station, check for leaks in the barrier material of the enclosure and take corrective measures if leaks are found. If possible, increase the flow of dry air to that station.

4. Press the LOW RH button on the central alarm unit. If low R.H. is indicated at any station, the space may be receiving too much dry air from the dehumidifier unit, either due to unbalance of the air system, or from excessive dehumidifier operation due to leakage of water or humid air in one of the other spaces.

5. Adjust the station % R.H. control higher or lower as necessary by two or three percent to compensate for air distribution limitations and to obtain optimum operation.

6. Use a portable hygrometer such as Hygrodynamics 3095 Portable Hygrometer Indicator, or a sling psychrometer and check each station area for balance.

10 V. MAINTENANCE

A. Functional Check Procedure

1. A periodic check should be performed to ascertain that the system is functioning properly. Refer to INSTALLATION, Paragraphs E and F.

2. If a component fails to respond to the test, downtime can be reduced by replacing the defective component with a spare. Return the defective component to HYGRODYNAMICS for repair.

B. Troubleshooting

1. Central Alarm Panel

a. Check the power supply. If all lights on the Central Alarm panel fail to light when the TEST switch is depressed, loss of power is indicated. Check fuse, power source, and wiring.

b. Lamps. Replace the lamps on the alarm panel that fail to light when the TEST switch is depressed.

c. Percent R.H. control settings on station units. Incorrect settings on the station units can indicate trouble that does not exist. Check all settings on the station units.

d. Power at station units. Loss of power at any station will cause the alarm light to go ON.

2. Station Control Units

a. Each station unit contains one 3228M Humistat and one 3295 Humistat. Each Humistat has potentiometers that are factory set for proper operation. The potentiometers are not adjustable in the field and the settings should not be changed.

b. If the system check (INSTALLATION Sec., III, Par. E) indicates trouble in a 3262 station unit, remove the sensors from all units and perform the following tests.

(1) Turn power OFF on all station units and short circuit RED sensor sockets with a piece of bus wire or a paper clip.

11 CAUTION

Always cut power OFF while making bare-wire connections in sensor socket. DO NOT HANDLE EXPOSED BUS WIRE WHEN CONDUCTING TESTS WITH POWER ON.

(2) Turn power ON and allow warm-up time. Turn the % R.H. control to less than 28% R.H. The dehumidifier unit should turn ON when the control knob is turned CCW toward the stop and it should turn OFF when the knob is turned CW toward 28% R.H.

(3) Turn power OFF and shortcircuit the ORANGE sensor (left side) socket (leave the short circuit in the 2nd ORANGE sensor socket)(right side). Re-energize, allow warm-up time and turn knob beyond 42% R.H.

(4) Turn the % R.H. control counterclockwise gradually. The alarm light for that station should go ON when the control indicates approximately 39% (+2% RH). The alarm light should go OFF when the knob is turned beyond 42% R.H. c. The tests performed in b. above, are sufficiently accurate to indicate proper operation of the 3262 station unit. For more accurate tests a calibrated variable resistance is substituted for the ORANGE sensor; For example, when the station unit is set at 34% R.H. the dehumidifier unit should be activated at approximately 36,000 ohms resistance and should turn OFF at approximately 60,000 ohms. The alarm light should go ON at approximately 12K and OFF at approximately 16K. d. Field repair of these units is not recommended. Units which do not operate properly should be replaced and the defective unit returned to HYGRODYNAMICS for repair or adjustment. e. The 3295 low R.H. alarm Humistat in the right side sensor circuit is factory- set to operate at 25% RH. The alarm contacts (1 and 2) should close when the short circuit is removed from the right sensor socket and open when the sensor sockets contacts are short circuited. A calibrated resistance can also be used to test the Humistat. The dry-alarm contacts should close when the resistance is between 400K and 300K.

Units which do not operate properly should be replaced and the defective unit returned to HYGRODYNAMICS for repair.

12 3. Hygrosensor

a. In clean atmospheres, the Hygrosensors have a very long life and good service is expected in this application. However, their calibration can be altered by certain contaminants and a periodic check of system performance is recommended.

b. At least twice a year, once in the summer and once in the winter, an independent precision hygrometer such as the Hygrodynamics 3095 Portable Electronic Hygrometer, or a sling psychrometer should be used to check conditions in each station area.

c. If the tests indicate a major shift in sensor calibration, the sensors should be replaced with spare sensors and the suspected sensors returned to HYGRODYNAMICS for check and re-calibration.

VI. REPLACEMENT AND SPARE PARTS

Description Part No.

Hygrosensor, Orange Band (2 required) 4817

Central Alarm Unit only 9333

Station Control/Alarm Unit 3262

Power Relay, 115VAC, SPDT 3400603

Humistat PC Board Assembly, Dual Relay 3228M

Humistat PC Board Assembly, Low RH Alarm 3297

Capacitor, 0.047 mf, 600 VDC 0400102 (Sprague 160P-6TM-S47)

Bulb, 6-watt, Candelabra Screw Base 1300304 (Ge#6S6)

Fuse, Type 3AG, 0.8-amp, 125V, Slo-Blo 2400112 (313.800)

Point Knob (% R.H. Control) (Raytheon 70-4-2)

13 ************************************************************************************************* HYGRODYNAMICS LIMITED WARRANTY

NEWPORT SCIENTIFIC, INC. warrants that all equipment manufactured by NSI shall be free from defects in material and workmanship which might impair its usefulness. SELLER DOES NOT WARRANT THAT THE EQUIPMENT IS FIT FOR ANY PARTICULAR USE. THERE ARE NO WARRANTIES WHICH EXTEND BEYOND THE DESCRIPTION ON THE FACE HEREOF; the obligation under this warranty is limited to repairing or replacing, at Seller's factory, any defective parts which, when returned by the buyer, transportation prepaid, examination discloses to have been factory defective. The time limit of this warranty is ONE YEAR from date of shipment of new equipment, SIX MONTHS from date of shipment of Hygrodynamics Wide- Range Sensors and THREE MONTHS from date of shipment of Hygrodynamics Narrow-Range Sensors and repaired equipment. THIS WARRANTY IS EXPRESSLY IN LIEU OF OTHER WARRANTIES. Seller shall not be held liable for any special, indirect, consequential damages arising out of this warranty or any breach thereof, of any defect in or failure or malfunction of the equipment and materials are further subject to tolerances and variations consistent with usages of trade. This warranty shall run in favor only of the purchaser from Seller and may not be passed on or represented on behalf of Seller to any subsequent purchaser.

WARRANTIES: OTHER PRODUCTS

NEWPORT SCIENTIFIC, INC. makes no express or implied warranty as to items, which are the products of other manufacturers. Seller shall use its best efforts to obtain from the manufacturer, in accordance with its customary practice, the repair or replacement of such products may prove defective in workmanship or material. The foregoing states the entire liability in respect to such products, except as an authorized executive of the corporation may otherwise agree in writing.

In the case of special equipment or modifications to standard equipment manufactured at the request of the buyer, under buyer-approved specifications, buyer will indemnify Seller against the risk damages due to patent infringement.