Transient overvoltage (surge) protection
UK OFFICE MIDDLE EAST OFFICE
Thomas & Betts Limited Thomas & Betts Ltd. Br. Furse Office 724 6WA West Wing Wilford Road Dubai Airport Free Zone Nottingham PO Box 54567 NG2 1EB Dubai United Kingdom United Arab Emirates ❱ Amendment 1 of BS 7671 places a clear The latest amendment to the IET ❱ Why is transient overvoltage protection Degradation of electronic systems, however, responsibility for transient overvoltage Switchboard +44 (0)115 964 3700 Tel +971 (0)4 609 1635 Wiring Regulations 17th Edition so important? begins at much lower overvoltage levels and protection on electrical system designers (BS 7671) brings into sharp focus the can cause data losses, intermittent outages Transient overvoltages are short duration and installers. Fax +44 (0)115 986 0538 Fax +971 (0)4 609 1636 need to protect sensitive and critical and shorter equipment lifetimes (see Figure 3). surges in voltage between two or more electronic systems against transient For many in this sphere of work, assessing the Sales tel +44 (0)115 964 3800 conductors (L-PE, L-N or N-PE), which can Where continuous operation of electronic overvoltages (surges). need for transient overvoltage protection will Sales fax +44 (0)115 986 0071 [email protected] reach up to 6 kV on 230 Vac power lines, systems is critical, for example in hospitals, be a new requirement. Amendment 1 of BS 7671, effective from and generally result from: banking and most public services, degradation must be avoided by ensuring these transient Defining when and where to install SPDs can 1st January 2012, requires all electrical Atmospheric origin (lightning activity) [email protected] overvoltages, which occur between L-N, are be a complex process, and sourcing the right system designs and installations to be through resistive or inductive coupling SOUTH EAST ASIA OFFICE limited below the impulse immunity of expertise can often be as important as www.furse.com assessed against risk of transient overvoltages (see Figures 1 & 2), and/or of atmospheric origin, or from switching equipment. This can be calculated as twice specifying the right product. Electrical switching of inductive loads Thomas & Betts events, in line with its Sections 443 & 534. the peak operating voltage of the electrical That’s why we support our transient Asia (Singapore) Pte Ltd Transient overvoltages significantly damage system, if unknown (i.e. approximately 715 V Section 443 defines the criteria for risk overvoltage solutions with EUROPEAN HEADQUARTERS and degrade electronic systems. for 230 V systems). CPD-accredited seminars 10 Ang Mo Kio Street 65 assessment, whereas Section 534 describes Outright damage to sensitive electronic Protection against transient overvoltages and training, including: #06-07 Techpoint the selection and installation of suitable Surge Thomas & Betts Protective Devices (SPDs), where required, for systems, such as computers etc, occurs when can be achieved through installation of a Transient overvoltage protection Transient overvoltage protection Seminars are conducted at customer premises European Centre SA Singapore 569059 effective transient overvoltage protection. transient overvoltages between L-PE or N-PE coordinated set of SPDs at appropriate points to BS 7671 to BS EN 62305 or at our head office in Nottingham, UK. BSI ™ exceed the withstand voltage of the electrical in the electrical system, in line with BS 7671 Whilst concerned with protection of AC 200 Chaussée de Waterloo equipment (i.e. above 1.5 kV for Category I Section 534 and the guidance provided in Providing key guidance on the risk Detailing the protection requirements To arrange a seminar, or for more information Tel +65 6720 8828 power supplies, BS 7671 does make clear equipment to BS 7671 Tables 44.3 & 44.4). this publication. assessment principles defined within for electrical and electronic systems on protecting your installations against B-1640 Rhode-St-Genèse UKAS QUALITY the need to protect all incoming/outgoing Fax +65 6720 8780 MANAGEMENT Section 443, plus selection and installation within structures, in accordance with transient overvoltages, contact us directly on: Equipment damage leads to unexpected Selecting SPDs with lower (i.e. better) voltage Belgium 003 metallic service lines, including data, signal of SPDs in line with Section 534 of BS EN 62305-4, including the lightning and telecoms lines, following BS EN 62305. failures and expensive downtime, or risk of protection levels (Up) is a critical factor, BS 7671:2008 (+A1:2011). protection zone (LPZ) concept, and the [email protected] Q06054 fire/electric shock due to flashover, if especially where continuous usage of application and coordination of SPDs. +44 (0)115 964 3700 Tel +32 (0)2 359 8200 insulation breaks down. electronic equipment is essential. e-mail: [email protected] Fax +32 (0)2 359 8201
DAMAGE DAMAGE > 1.5 kV Degradation (L-PE/N-PE)
Safe Operating Area Degradation > 2x peak operating voltage (e.g. 715 V L-N)
Safe Operating Area www.tnb-europe.com Nominal Transient overvoltage protection Degradation system voltage (e.g. 230 V) DAMAGE to IET Wiring Regulations 17th Edition (BS 7671:2008+A1:2011) Figure 1: Resistive coupling Figure 2: Inductive coupling Figure 3: Equipment risk Resistively coupled transients are caused by differences Inductively coupled transients are caused by Degradation of electronic systems begins at lower The content of this Thomas & Betts publication has been carefully checked for accuracy at the time of print. However, Thomas & Betts in potential between two connected earths. electromagnetic pick-up. transient overvoltage levels and affects critical doesn’t give any warranty of any kind, express or implied, in this respect and shall not be liable for any loss or damage that may result electronic systems whenever the impulse immunity from any use or as a consequence of any inaccuracies in or any omissions from the information which it may contain. E&OE. Energy from ground strikes flows away through the A lightning discharge gives rise to an of the equipment is compromised. Copyright Thomas & Betts Corp. 2012. Copyright in these pages is owned by Thomas & Betts except where otherwise indicated. No part of path of least resistance, and increases the potential in electromagnetic field. If metallic services, such this publication may be reproduced, copied or transmitted in any form or by any means, without our prior written permission. Images, local earths, cabling and electronic circuitry. as overhead power lines, pass through this Damage occurs when a transient overvoltage trade marks, brands, designs and technology are also protected by other intellectual property rights and may not be reproduced or field a voltage will be picked up by, or induced exceeds the withstand voltage of electrical and appropriated in any manner without written permission of their respective owners. Thomas & Betts reserves the right to change and Where these are linked to separate earths by a metallic on to, the line. electronic equipment. improve any product specifications or other mentions in the publication at its own discretion and at any time. These conditions of use are service line, the potential is shared, creating transient governed by the laws of the Netherlands and the courts of Amsterdam shall have exclusive jurisdiction in any dispute. overvoltages as the current attempts to flow.
ESP-BS7671-0612 Transient overvoltage (surge) protection
UK OFFICE MIDDLE EAST OFFICE
Thomas & Betts Limited Thomas & Betts Ltd. Br. Furse Office 724 6WA West Wing Wilford Road Dubai Airport Free Zone Nottingham PO Box 54567 NG2 1EB Dubai United Kingdom United Arab Emirates ❱ Amendment 1 of BS 7671 places a clear The latest amendment to the IET ❱ Why is transient overvoltage protection Degradation of electronic systems, however, responsibility for transient overvoltage Switchboard +44 (0)115 964 3700 Tel +971 (0)4 609 1635 Wiring Regulations 17th Edition so important? begins at much lower overvoltage levels and protection on electrical system designers (BS 7671) brings into sharp focus the can cause data losses, intermittent outages Transient overvoltages are short duration and installers. Fax +44 (0)115 986 0538 Fax +971 (0)4 609 1636 need to protect sensitive and critical and shorter equipment lifetimes (see Figure 3). surges in voltage between two or more electronic systems against transient For many in this sphere of work, assessing the Sales tel +44 (0)115 964 3800 conductors (L-PE, L-N or N-PE), which can Where continuous operation of electronic overvoltages (surges). need for transient overvoltage protection will Sales fax +44 (0)115 986 0071 [email protected] reach up to 6 kV on 230 Vac power lines, systems is critical, for example in hospitals, be a new requirement. Amendment 1 of BS 7671, effective from and generally result from: banking and most public services, degradation must be avoided by ensuring these transient Defining when and where to install SPDs can 1st January 2012, requires all electrical Atmospheric origin (lightning activity) [email protected] overvoltages, which occur between L-N, are be a complex process, and sourcing the right system designs and installations to be through resistive or inductive coupling SOUTH EAST ASIA OFFICE limited below the impulse immunity of expertise can often be as important as www.furse.com assessed against risk of transient overvoltages (see Figures 1 & 2), and/or of atmospheric origin, or from switching equipment. This can be calculated as twice specifying the right product. Electrical switching of inductive loads Thomas & Betts events, in line with its Sections 443 & 534. the peak operating voltage of the electrical That’s why we support our transient Asia (Singapore) Pte Ltd Transient overvoltages significantly damage system, if unknown (i.e. approximately 715 V Section 443 defines the criteria for risk overvoltage solutions with EUROPEAN HEADQUARTERS and degrade electronic systems. for 230 V systems). CPD-accredited seminars 10 Ang Mo Kio Street 65 assessment, whereas Section 534 describes Outright damage to sensitive electronic Protection against transient overvoltages and training, including: #06-07 Techpoint the selection and installation of suitable Surge Thomas & Betts Protective Devices (SPDs), where required, for systems, such as computers etc, occurs when can be achieved through installation of a Transient overvoltage protection Transient overvoltage protection Seminars are conducted at customer premises European Centre SA Singapore 569059 effective transient overvoltage protection. transient overvoltages between L-PE or N-PE coordinated set of SPDs at appropriate points to BS 7671 to BS EN 62305 or at our head office in Nottingham, UK. BSI ™ exceed the withstand voltage of the electrical in the electrical system, in line with BS 7671 Whilst concerned with protection of AC 200 Chaussée de Waterloo equipment (i.e. above 1.5 kV for Category I Section 534 and the guidance provided in Providing key guidance on the risk Detailing the protection requirements To arrange a seminar, or for more information Tel +65 6720 8828 power supplies, BS 7671 does make clear equipment to BS 7671 Tables 44.3 & 44.4). this publication. assessment principles defined within for electrical and electronic systems on protecting your installations against B-1640 Rhode-St-Genèse UKAS QUALITY the need to protect all incoming/outgoing Fax +65 6720 8780 MANAGEMENT Section 443, plus selection and installation within structures, in accordance with transient overvoltages, contact us directly on: Equipment damage leads to unexpected Selecting SPDs with lower (i.e. better) voltage Belgium 003 metallic service lines, including data, signal of SPDs in line with Section 534 of BS EN 62305-4, including the lightning and telecoms lines, following BS EN 62305. failures and expensive downtime, or risk of protection levels (Up) is a critical factor, BS 7671:2008 (+A1:2011). protection zone (LPZ) concept, and the [email protected] Q06054 fire/electric shock due to flashover, if especially where continuous usage of application and coordination of SPDs. +44 (0)115 964 3700 Tel +32 (0)2 359 8200 insulation breaks down. electronic equipment is essential. e-mail: [email protected] Fax +32 (0)2 359 8201
DAMAGE DAMAGE > 1.5 kV Degradation (L-PE/N-PE)
Safe Operating Area Degradation > 2x peak operating voltage (e.g. 715 V L-N)
Safe Operating Area www.tnb-europe.com Nominal Transient overvoltage protection Degradation system voltage (e.g. 230 V) DAMAGE to IET Wiring Regulations 17th Edition (BS 7671:2008+A1:2011) Figure 1: Resistive coupling Figure 2: Inductive coupling Figure 3: Equipment risk Resistively coupled transients are caused by differences Inductively coupled transients are caused by Degradation of electronic systems begins at lower The content of this Thomas & Betts publication has been carefully checked for accuracy at the time of print. However, Thomas & Betts in potential between two connected earths. electromagnetic pick-up. transient overvoltage levels and affects critical doesn’t give any warranty of any kind, express or implied, in this respect and shall not be liable for any loss or damage that may result electronic systems whenever the impulse immunity from any use or as a consequence of any inaccuracies in or any omissions from the information which it may contain. E&OE. Energy from ground strikes flows away through the A lightning discharge gives rise to an of the equipment is compromised. Copyright Thomas & Betts Corp. 2012. Copyright in these pages is owned by Thomas & Betts except where otherwise indicated. No part of path of least resistance, and increases the potential in electromagnetic field. If metallic services, such this publication may be reproduced, copied or transmitted in any form or by any means, without our prior written permission. Images, local earths, cabling and electronic circuitry. as overhead power lines, pass through this Damage occurs when a transient overvoltage trade marks, brands, designs and technology are also protected by other intellectual property rights and may not be reproduced or field a voltage will be picked up by, or induced exceeds the withstand voltage of electrical and appropriated in any manner without written permission of their respective owners. Thomas & Betts reserves the right to change and Where these are linked to separate earths by a metallic on to, the line. electronic equipment. improve any product specifications or other mentions in the publication at its own discretion and at any time. These conditions of use are service line, the potential is shared, creating transient governed by the laws of the Netherlands and the courts of Amsterdam shall have exclusive jurisdiction in any dispute. overvoltages as the current attempts to flow.
ESP-BS7671-0612
Transient overvoltage risk assessment SPD selection & installation Protection for 230/400 V TN‐S or TN‐C‐S supplies
No external lightning No external lightning External lightning protection External lightning protection Sections 443 and 534 of BS 7671 cover Protection is required where: The flowchart below (Figure 4) defines ❱ Assessing installation requirements BS 7671 Section 534 therefore recommends Figure 5 shows a typical installation on a ❱ SPD performance Controlled installation to BS 7671 of SPDs protection system fitted protection system fitted system fitted system fitted transient overvoltage risk and SPD risk assessment in terms of potential that SPDs are installed at key locations in the 230/400 V TN-C-S/TN-S system using Furse Underground mains supply feed Exposed overhead mains Multiple connected metallic services No. of services unknown The expected transient overvoltages BS 7671 Section 534 focuses guidance The most important parameter for SPD with lower (better) voltage protection levels selection/installation on AC power supplies. consequential losses. electrical system: SPDs, to meet the requirements of BS 7671. (U ), and short connecting leads optimises supply feed would exceed the withstand voltage1 of on selection and installation of SPDs performance is its voltage protection p LPS LPS protection at terminal equipment by: ❱ Determining risk to BS 7671 installed equipment (as defined by Note, as per the flowchart, risk of to limit transient overvoltages on the As close as practicable to the origin of the The illustration demonstrates how effective level (Up) (534.2.3.1.1) and not its Tables 44.3 & 44.4 of BS 7671), and consequential loss to human life, public AC power supply. installation (usually in the main distribution protection comprises a service entrance SPD Limiting additive inductive voltages on the BS 7671 Section 443 establishes that protection energy withstand (e.g. Iimp) (Fig 16A.5). services or to commercial/industrial activity board after the meter) (534.2.1) to divert high energy lightning currents to SPD's connecting leads Power against transient overvoltages is required in an The risk of consequential loss (to life, Section 443 states that 'transient overvoltages The lower the voltage protection level (Up), always results in the need to install earth, followed by downstream SPDs at Ground Ground Ground Ground installation which includes a structural lightning property or provision of service) is transmitted by the supply distribution system As close as practicable to sensitive the better the protection afforded to the Reducing risk of downstream voltage Level Level Level Level protection measures (443.2.4 Note 2). appropriate points to protect sensitive and protection system (LPS), and/or connected deemed unacceptable (443.2.4) are not significantly attenuated downstream equipment (sub-distribution level), withstand voltage or impulse immunity of oscillations which can reach up to twice SPD selection notes critical equipment. Power Power Power metallic service lines at risk from lightning. Following this process, where the need for in most installations' (443.1.1 NOTE 3). and local to critical equipment (534.2.1) the equipment (534.2.3.1.1). the SPD's U and cause damage at Data LPL refers to Lightning If terminal equipment to Category I of Table p Telecom protection is established, BS 7671 requires equipment (534.2.3.1.2) Unknown Protection Level, as defined It details protection requirements for 44.3, such as computers/laptops etc., is to be Equally, short connecting leads between Water the selection and installation of SPDs on Gas { by BS EN/IEC 62305. AC power lines, and refers to BS EN 62305 connected to the fixed electrical installation, Service entrance/ Sub-distribution board Terminal equipment the SPD and conductors are paramount to Furse SPDs are designed with industry leading the AC power supply in accordance with regarding additional metallic service lines (data, it must be protected against transient Main distribution board Line Line keep transient overvoltages to a minimum low voltage protection levels (Up), and many Voltage protection level (Up) its Section 534. length length at the equipment terminals signal & telecoms). overvoltages (Table 44.4). > 10 m > 10 m (see Figure 6). include a remote display option to ensure SPD OCPD L1 L1 positioning as close as possible to conductors. should be lower than the withstand voltage of L2 L2 OCPD START sensitive equipment (1.5 kV L3 L3 Category I) or the impulse 3 Phase 400 V immunity of critical Risk of direct lightning YES N N < 0.25 m equipment (approx. 715 V (BS EN 62305) or lightning protection PEN PE OCPD Service entrance, system installed? (443.1.1) after electricity for 230/400 V supplies) (534.2.3.1). SPD meter (Main NO LL1 N N1 distribution PATENT 125 AgL Type 3 SPD performance APPLIED FOR ESP 240D1 STATUS INDICATION ESP 415 D1 Seriesor ESP 415 M1 Series ESP 415/III/TNSor ESP 415 M2 Series ESP 415 D1 Series or ESP 415 M1 Series For LPL I & II or For LPL III & IV L N T1 Iimp 4kA B board (MDB) In 20kA Uc 280Vac 47-63Hz GREEN FULL PROTECTION T2 Imax 40kA C applies at equipment GREEN & RED REDUCED PROTECTION EN/IEC 61643 T3 Uoc 6kV D OCPD OCPD (replace unit) (for electronics ESP 415/I/TNS ESP 415/III/TNS Install lightning current TYPE 1 SPD REDNO PROTECTION WARNING: If lit / flashing disconnect ! ALTERNATIVE unit & check Neutral Overhead line supplying the to Earth voltage YES Risk of located near or or terminals. To BS EN 62305 an or combined TYPE 1+2 SPD on main STATUSSTATUS 11 building at risk of direct strike - switching 14 12 SPD's voltage protection level distribution board to prevent transient MDB before SDB) ESP 415 M4 ESP 415 M2 simplified risk see BS EN 62305 (443.1.1) (Up) should be no more than L L' L2 L2' L3 L3' N N' (for electronics (for electronics assessment dangerous flashover (534.2.1) L1 L2 L3 N Main earthing 250 AgL If RED replace located near 600 V when tested to PATENT located near APPLIED terminal or < 0.25 m (443.2.4). NO FOR ESP 415/I/TNS Enhanced connecting MDB before SDB) MDB before SDB) BS EN 61643-11 Class III test. Enhanced Mains Protector Mains EN/IEC 61643 Protector conductor bar limp = 25kA/mode lmax = 100kA/mode ln = 25kA/mode All the Furse Combined Type Uc = 320VAC Up < 1.4kV Installation presents higher risk Ures(limp) < 1.3kV PE 1+2+3 & Type 2+3 SPDs Protection against transient STATUS 11 (e.g. fire) or requires higher reliability 14 12 Consider following NO Figure 6: Critical length of connecting conductors (534.2.9) shown in the selection chart from transient overvoltages, overvoltages not required 3 Phase 400 V levels of consequences ESP 415/I/TNS ESP 415 D1/LCD Full Mode Fixed equipment Critical equipment meet this requirement. (443.2.1, 443.2.2) if equipment from transient including electrical switching Type 1+2 SPD Type 1+2+3 SPD (e.g. UPS) (e.g. hospital SPD connections should be kept as short as possible ideally below 0.25 m between SPD, live conductors & earth, 1 Phase 230 V withstand voltage1 to Table 44.3 equipment) All Furse SPDs shown have overvoltages, including (443.2.2 Note) - see BS EN 62305 but in any case not more than 0.5 m, to reduce risk of additive inductive voltage drops across the conductors. Sub‐distribution been tested to at least the electric switching YES Main earthing terminal board (SDB) ‐ For 3 Phase 400 V: For 1 Phase 230 V: minimum nominal discharge Install coordinated set of or or SPD coordination Protect additional metallic services located ESP 415 D1 Series, or ESP 240 D1 Series, or current (I ) of 5 kA 8/20 transient overvoltage SPDs for ESP 415/I/TNS with Type 1 OCPD : Overcurrent protective device (fuse) ESP 415 D1/LCD with Type 2 Combined Type 2+3 Plug-in ESP MC with Type 3 ❱ ❱ nspd performance installed at performance installed at sub- performance of the SPD performance protects critical > 10 m from ESP 415 M1 Series ESP 240 M1 Series waveform, for TN-S or Consequences related to equipment protection (e.g. TYPE 2 service entrance to divert distribution protects fixed installed at sub-distribution equipment at local level Smaller installations may require only BS 7671 is focused towards protection YES MDB feeding TN-C-S supplies as specified human life, e.g. safety/medical or Combined TYPE 2+3) high energy lightning equipment on the electrical protects downstream against switching transients. a single SPD (534.2.2). of AC power supplies. electronic currents to earth, and installation against transient sensitive equipment against by BS 7671 (534.2.3.4.1). equipment? (443.2.4) on distribution boards feeding remove risk of flashover. overvoltages. transient overvoltages. equipment However where the protective distance For protection measures against direct Note: I as defined by sensitive electronic nspd between SPD and electrical equipment lightning strikes, and against transient BS 7671 correlates with I of NO equipment (534.2.6) Figure 5: Typical installation on a 230/400 V TN-C-S/TN-S system using Furse SPDs, to meet the requirements of BS 7671 n exceeds 10 m, additional downstream SPDs overvoltages on additional metallic service BS EN/IEC 61643. may be needed to counter voltage oscillations lines (e.g. data, signal & telecoms), BS 7671 Critical terminal Consequences related to loss of Where a service entrance YES Selecting appropriate SPDs Transient overvoltage SPDs (Type 2 and Type 3, These SPDs, classed as enhanced SPDs to equipment ‐ ESP MC public service, e.g. IT centres ❱ (534.2.3.1.1). refers to BS EN 62305 (534.1 NOTE 2). Type 1 SPD is required, it or Combined Type 1+2+3 and Type 2+3) BS EN 62305, offer technical and economic located > 10 m ESP MC/TN/RJ11 (e.g. for fax machines) and museums? (443.2.4) SPDs are classified by Type within SPDs installed on the same conductor should Full protection of electronic systems can only from SDB ESP MC/Cat‐5e (e.g. for servers) should be tested to Check if data, signal should therefore be installed downstream of advantages over standard SPDs, providing: BS 7671 (534.2.1), following the criteria coordinate with each other to ensure effective, be achieved if all incoming/outgoing metallic withstand lightning impulse NO and telecoms lines the service entrance. established in BS EN/IEC 62305. Combined equipotential bonding and continuous protection (534.2.1 & 534.2.3.6). services, including data, signal and telecoms currents (Iimp) to require protection These SPDs further protect against those transient overvoltage protection lines are protected. BS EN/IEC 61643. Consequences related to loss Where a building includes a structural LPS, or The selection chart (right) defines the appropriate YES (443.1, 534.2.1) transient overvoltages caused by indirect (Type 1+2 & Type 1+2+3) Standard Remote Display Weatherproof Status of commercial activity, e.g. connected overhead metallic services at risk Furse SPDs to achieve coordination on a SPD Performance 1 Remote displays enable positioning of an SPD The value of Iimp for an lightning (via resistive or inductive coupling) Part No. Option Part No.1 enclosure2 indication installation should be hotels, banks, farms? (443.2.4) from a direct lightning strike, equipotential Full mode (common and differential mode) 230/400 V TN-S or TN-C-S system, dependent close to conductors with the display mounted in and electrical switching of inductive loads. calculated according to bonding SPDs (Type 1 or Combined Type 1+2) protection, essential to safeguard sensitive on installation requirement, in line with BS 7671. ESP 415/I/TNS - WBX D4 Combined Type 1+2 LED an easily visible position. Data/ WBX D4 BS EN 62305. Where it NO must be installed at the service entrance, to Combined Type SPDs (such as the Furse electronic equipment from all types of Telecom ESP 415/III/TNS - Combined Type 1+2 LED 2 For TT systems, contact Furse. Weatherproof enclosures are rated to IP65 or cannot be calculated, the remove risk of flashover (534.2.3.4.2). ESP D1 Series and ESP M1/M2/M4 Series) transient overvoltage - lightning & ESP 415 M4 ESP 415 M4R WBX M4 Combined Type 1+2+3 LED above and enable mounting of SPDs in adverse SPD should have capability Consequences related to All Furse SPD sets for power and data lines are Power ESP 415 M2 ESP 415 M2R WBX M2 Combined Type 1+2+3 LED YES Protection against transient significantly simplify the SPD selection process, switching (524.2.2 NOTE 1), and environments. They should be used where the individuals or groups, e.g. Installation of Type 1 SPDs alone however specifically designed to ensure coordination. ESP 415 D1 ESP 415 D1R WBX D8 Combined Type 1+2+3 LED not less than 12.5 kA per overvoltages not required if equipment whether installing at the service entrance or SPD is not mounted within a distribution board. 1 does not provide protection to electronic Effective SPD coordination within a single WBX D8 Combined Type 1+2+3 LCD3 mode to PE or common residential buildings? (443.2.4) withstand voltage to Table 44.3 downstream in the electrical system. Following BS 7671, installation of Furse SPDs ESP 415 D1/LCD ESP 415 D1R/LCD systems (534.2.1 NOTE 3). unit versus installation of multiple standard WBX 4 Combined Type 1+2+3 LED 3 LCD remote display includes rotating screen text mode (534.2.3.4.2). at service entrance, sub-distribution and at ESP 415 M1 ESP 415 M1R Type SPDs to protect terminal equipment ESP 240 D1 - WBX D4 Combined Type 1+2+3 LED (by 90˚) for optimal positioning and viewing, as For more information on SPD Figure 4: Transient overvoltage risk assessment to BS 7671 critical electrical equipment, will ensure IMPORTANT: Equipment is ONLY protected against ESP 240 M1 - WBX 3 Combined Type 1+2+3 LED well as audible status warning. selection, contact Furse. optimal, consistent protection against transient overvoltages if all incoming / outgoing ESP MC - - Combined Type 2+3 LED 1 Note, withstand voltage protects only against failure of equipment. For continuous operation of critical equipment, impulse immunity must be protected. transient overvoltages. mains and data lines have protection fitted.
Transient overvoltage risk assessment SPD selection & installation Protection for 230/400 V TN‐S or TN‐C‐S supplies
No external lightning No external lightning External lightning protection External lightning protection Sections 443 and 534 of BS 7671 cover Protection is required where: The flowchart below (Figure 4) defines ❱ Assessing installation requirements BS 7671 Section 534 therefore recommends Figure 5 shows a typical installation on a ❱ SPD performance Controlled installation to BS 7671 of SPDs protection system fitted protection system fitted system fitted system fitted transient overvoltage risk and SPD risk assessment in terms of potential that SPDs are installed at key locations in the 230/400 V TN-C-S/TN-S system using Furse Underground mains supply feed Exposed overhead mains Multiple connected metallic services No. of services unknown The expected transient overvoltages BS 7671 Section 534 focuses guidance The most important parameter for SPD with lower (better) voltage protection levels selection/installation on AC power supplies. consequential losses. electrical system: SPDs, to meet the requirements of BS 7671. (U ), and short connecting leads optimises supply feed would exceed the withstand voltage1 of on selection and installation of SPDs performance is its voltage protection p LPS LPS protection at terminal equipment by: ❱ Determining risk to BS 7671 installed equipment (as defined by Note, as per the flowchart, risk of to limit transient overvoltages on the As close as practicable to the origin of the The illustration demonstrates how effective level (Up) (534.2.3.1.1) and not its Tables 44.3 & 44.4 of BS 7671), and consequential loss to human life, public AC power supply. installation (usually in the main distribution protection comprises a service entrance SPD Limiting additive inductive voltages on the BS 7671 Section 443 establishes that protection energy withstand (e.g. Iimp) (Fig 16A.5). services or to commercial/industrial activity board after the meter) (534.2.1) to divert high energy lightning currents to SPD's connecting leads Power against transient overvoltages is required in an The risk of consequential loss (to life, Section 443 states that 'transient overvoltages The lower the voltage protection level (Up), always results in the need to install earth, followed by downstream SPDs at Ground Ground Ground Ground installation which includes a structural lightning property or provision of service) is transmitted by the supply distribution system As close as practicable to sensitive the better the protection afforded to the Reducing risk of downstream voltage Level Level Level Level protection measures (443.2.4 Note 2). appropriate points to protect sensitive and protection system (LPS), and/or connected deemed unacceptable (443.2.4) are not significantly attenuated downstream equipment (sub-distribution level), withstand voltage or impulse immunity of oscillations which can reach up to twice SPD selection notes critical equipment. Power Power Power metallic service lines at risk from lightning. Following this process, where the need for in most installations' (443.1.1 NOTE 3). and local to critical equipment (534.2.1) the equipment (534.2.3.1.1). the SPD's U and cause damage at Data LPL refers to Lightning If terminal equipment to Category I of Table p Telecom protection is established, BS 7671 requires equipment (534.2.3.1.2) Unknown Protection Level, as defined It details protection requirements for 44.3, such as computers/laptops etc., is to be Equally, short connecting leads between Water the selection and installation of SPDs on Gas { by BS EN/IEC 62305. AC power lines, and refers to BS EN 62305 connected to the fixed electrical installation, Service entrance/ Sub-distribution board Terminal equipment the SPD and conductors are paramount to Furse SPDs are designed with industry leading the AC power supply in accordance with regarding additional metallic service lines (data, it must be protected against transient Main distribution board Line Line keep transient overvoltages to a minimum low voltage protection levels (Up), and many Voltage protection level (Up) its Section 534. length length at the equipment terminals signal & telecoms). overvoltages (Table 44.4). > 10 m > 10 m (see Figure 6). include a remote display option to ensure SPD OCPD L1 L1 positioning as close as possible to conductors. should be lower than the withstand voltage of L2 L2 OCPD START sensitive equipment (1.5 kV L3 L3 Category I) or the impulse 3 Phase 400 V immunity of critical Risk of direct lightning YES N N < 0.25 m equipment (approx. 715 V (BS EN 62305) or lightning protection PEN PE OCPD Service entrance, system installed? (443.1.1) after electricity for 230/400 V supplies) (534.2.3.1). SPD meter (Main NO LL1 N N1 distribution PATENT 125 AgL Type 3 SPD performance APPLIED FOR ESP 240D1 STATUS INDICATION ESP 415 D1 Seriesor ESP 415 M1 Series ESP 415/III/TNSor ESP 415 M2 Series ESP 415 D1 Series or ESP 415 M1 Series For LPL I & II or For LPL III & IV L N T1 Iimp 4kA B board (MDB) In 20kA Uc 280Vac 47-63Hz GREEN FULL PROTECTION T2 Imax 40kA C applies at equipment GREEN & RED REDUCED PROTECTION EN/IEC 61643 T3 Uoc 6kV D OCPD OCPD (replace unit) (for electronics ESP 415/I/TNS ESP 415/III/TNS Install lightning current TYPE 1 SPD REDNO PROTECTION WARNING: If lit / flashing disconnect ! ALTERNATIVE unit & check Neutral Overhead line supplying the to Earth voltage YES Risk of located near or or terminals. To BS EN 62305 an or combined TYPE 1+2 SPD on main STATUSSTATUS 11 building at risk of direct strike - switching 14 12 SPD's voltage protection level distribution board to prevent transient MDB before SDB) ESP 415 M4 ESP 415 M2 simplified risk see BS EN 62305 (443.1.1) (Up) should be no more than L L' L2 L2' L3 L3' N N' (for electronics (for electronics assessment dangerous flashover (534.2.1) L1 L2 L3 N Main earthing 250 AgL If RED replace located near 600 V when tested to PATENT located near APPLIED terminal or < 0.25 m (443.2.4). NO FOR ESP 415/I/TNS Enhanced connecting MDB before SDB) MDB before SDB) BS EN 61643-11 Class III test. Enhanced Mains Protector Mains EN/IEC 61643 Protector conductor bar limp = 25kA/mode lmax = 100kA/mode ln = 25kA/mode All the Furse Combined Type Uc = 320VAC Up < 1.4kV Installation presents higher risk Ures(limp) < 1.3kV PE 1+2+3 & Type 2+3 SPDs Protection against transient STATUS 11 (e.g. fire) or requires higher reliability 14 12 Consider following NO Figure 6: Critical length of connecting conductors (534.2.9) shown in the selection chart from transient overvoltages, overvoltages not required 3 Phase 400 V levels of consequences ESP 415/I/TNS ESP 415 D1/LCD Full Mode Fixed equipment Critical equipment meet this requirement. (443.2.1, 443.2.2) if equipment from transient including electrical switching Type 1+2 SPD Type 1+2+3 SPD (e.g. UPS) (e.g. hospital SPD connections should be kept as short as possible ideally below 0.25 m between SPD, live conductors & earth, 1 Phase 230 V withstand voltage1 to Table 44.3 equipment) All Furse SPDs shown have overvoltages, including (443.2.2 Note) - see BS EN 62305 but in any case not more than 0.5 m, to reduce risk of additive inductive voltage drops across the conductors. Sub‐distribution been tested to at least the electric switching YES Main earthing terminal board (SDB) ‐ For 3 Phase 400 V: For 1 Phase 230 V: minimum nominal discharge Install coordinated set of or or SPD coordination Protect additional metallic services located ESP 415 D1 Series, or ESP 240 D1 Series, or current (I ) of 5 kA 8/20 transient overvoltage SPDs for ESP 415/I/TNS with Type 1 OCPD : Overcurrent protective device (fuse) ESP 415 D1/LCD with Type 2 Combined Type 2+3 Plug-in ESP MC with Type 3 ❱ ❱ nspd performance installed at performance installed at sub- performance of the SPD performance protects critical > 10 m from ESP 415 M1 Series ESP 240 M1 Series waveform, for TN-S or Consequences related to equipment protection (e.g. TYPE 2 service entrance to divert distribution protects fixed installed at sub-distribution equipment at local level Smaller installations may require only BS 7671 is focused towards protection YES MDB feeding TN-C-S supplies as specified human life, e.g. safety/medical or Combined TYPE 2+3) high energy lightning equipment on the electrical protects downstream against switching transients. a single SPD (534.2.2). of AC power supplies. electronic currents to earth, and installation against transient sensitive equipment against by BS 7671 (534.2.3.4.1). equipment? (443.2.4) on distribution boards feeding remove risk of flashover. overvoltages. transient overvoltages. equipment However where the protective distance For protection measures against direct Note: I as defined by sensitive electronic nspd between SPD and electrical equipment lightning strikes, and against transient BS 7671 correlates with I of NO equipment (534.2.6) Figure 5: Typical installation on a 230/400 V TN-C-S/TN-S system using Furse SPDs, to meet the requirements of BS 7671 n exceeds 10 m, additional downstream SPDs overvoltages on additional metallic service BS EN/IEC 61643. may be needed to counter voltage oscillations lines (e.g. data, signal & telecoms), BS 7671 Critical terminal Consequences related to loss of Where a service entrance YES Selecting appropriate SPDs Transient overvoltage SPDs (Type 2 and Type 3, These SPDs, classed as enhanced SPDs to equipment ‐ ESP MC public service, e.g. IT centres ❱ (534.2.3.1.1). refers to BS EN 62305 (534.1 NOTE 2). Type 1 SPD is required, it or Combined Type 1+2+3 and Type 2+3) BS EN 62305, offer technical and economic located > 10 m ESP MC/TN/RJ11 (e.g. for fax machines) and museums? (443.2.4) SPDs are classified by Type within SPDs installed on the same conductor should Full protection of electronic systems can only from SDB ESP MC/Cat‐5e (e.g. for servers) should be tested to Check if data, signal should therefore be installed downstream of advantages over standard SPDs, providing: BS 7671 (534.2.1), following the criteria coordinate with each other to ensure effective, be achieved if all incoming/outgoing metallic withstand lightning impulse NO and telecoms lines the service entrance. established in BS EN/IEC 62305. Combined equipotential bonding and continuous protection (534.2.1 & 534.2.3.6). services, including data, signal and telecoms currents (Iimp) to require protection These SPDs further protect against those transient overvoltage protection lines are protected. BS EN/IEC 61643. Consequences related to loss Where a building includes a structural LPS, or The selection chart (right) defines the appropriate YES (443.1, 534.2.1) transient overvoltages caused by indirect (Type 1+2 & Type 1+2+3) Standard Remote Display Weatherproof Status of commercial activity, e.g. connected overhead metallic services at risk Furse SPDs to achieve coordination on a SPD Performance 1 Remote displays enable positioning of an SPD The value of Iimp for an lightning (via resistive or inductive coupling) Part No. Option Part No.1 enclosure2 indication installation should be hotels, banks, farms? (443.2.4) from a direct lightning strike, equipotential Full mode (common and differential mode) 230/400 V TN-S or TN-C-S system, dependent close to conductors with the display mounted in and electrical switching of inductive loads. calculated according to bonding SPDs (Type 1 or Combined Type 1+2) protection, essential to safeguard sensitive on installation requirement, in line with BS 7671. ESP 415/I/TNS - WBX D4 Combined Type 1+2 LED an easily visible position. Data/ WBX D4 BS EN 62305. Where it NO must be installed at the service entrance, to Combined Type SPDs (such as the Furse electronic equipment from all types of Telecom ESP 415/III/TNS - Combined Type 1+2 LED 2 For TT systems, contact Furse. Weatherproof enclosures are rated to IP65 or cannot be calculated, the remove risk of flashover (534.2.3.4.2). ESP D1 Series and ESP M1/M2/M4 Series) transient overvoltage - lightning & ESP 415 M4 ESP 415 M4R WBX M4 Combined Type 1+2+3 LED above and enable mounting of SPDs in adverse SPD should have capability Consequences related to All Furse SPD sets for power and data lines are Power ESP 415 M2 ESP 415 M2R WBX M2 Combined Type 1+2+3 LED YES Protection against transient significantly simplify the SPD selection process, switching (524.2.2 NOTE 1), and environments. They should be used where the individuals or groups, e.g. Installation of Type 1 SPDs alone however specifically designed to ensure coordination. ESP 415 D1 ESP 415 D1R WBX D8 Combined Type 1+2+3 LED not less than 12.5 kA per overvoltages not required if equipment whether installing at the service entrance or SPD is not mounted within a distribution board. 1 does not provide protection to electronic Effective SPD coordination within a single WBX D8 Combined Type 1+2+3 LCD3 mode to PE or common residential buildings? (443.2.4) withstand voltage to Table 44.3 downstream in the electrical system. Following BS 7671, installation of Furse SPDs ESP 415 D1/LCD ESP 415 D1R/LCD systems (534.2.1 NOTE 3). unit versus installation of multiple standard WBX 4 Combined Type 1+2+3 LED 3 LCD remote display includes rotating screen text mode (534.2.3.4.2). at service entrance, sub-distribution and at ESP 415 M1 ESP 415 M1R Type SPDs to protect terminal equipment ESP 240 D1 - WBX D4 Combined Type 1+2+3 LED (by 90˚) for optimal positioning and viewing, as For more information on SPD Figure 4: Transient overvoltage risk assessment to BS 7671 critical electrical equipment, will ensure IMPORTANT: Equipment is ONLY protected against ESP 240 M1 - WBX 3 Combined Type 1+2+3 LED well as audible status warning. selection, contact Furse. optimal, consistent protection against transient overvoltages if all incoming / outgoing ESP MC - - Combined Type 2+3 LED 1 Note, withstand voltage protects only against failure of equipment. For continuous operation of critical equipment, impulse immunity must be protected. transient overvoltages. mains and data lines have protection fitted.
Transient overvoltage risk assessment SPD selection & installation Protection for 230/400 V TN‐S or TN‐C‐S supplies
No external lightning No external lightning External lightning protection External lightning protection Sections 443 and 534 of BS 7671 cover Protection is required where: The flowchart below (Figure 4) defines ❱ Assessing installation requirements BS 7671 Section 534 therefore recommends Figure 5 shows a typical installation on a ❱ SPD performance Controlled installation to BS 7671 of SPDs protection system fitted protection system fitted system fitted system fitted transient overvoltage risk and SPD risk assessment in terms of potential that SPDs are installed at key locations in the 230/400 V TN-C-S/TN-S system using Furse Underground mains supply feed Exposed overhead mains Multiple connected metallic services No. of services unknown The expected transient overvoltages BS 7671 Section 534 focuses guidance The most important parameter for SPD with lower (better) voltage protection levels selection/installation on AC power supplies. consequential losses. electrical system: SPDs, to meet the requirements of BS 7671. (U ), and short connecting leads optimises supply feed would exceed the withstand voltage1 of on selection and installation of SPDs performance is its voltage protection p LPS LPS protection at terminal equipment by: ❱ Determining risk to BS 7671 installed equipment (as defined by Note, as per the flowchart, risk of to limit transient overvoltages on the As close as practicable to the origin of the The illustration demonstrates how effective level (Up) (534.2.3.1.1) and not its Tables 44.3 & 44.4 of BS 7671), and consequential loss to human life, public AC power supply. installation (usually in the main distribution protection comprises a service entrance SPD Limiting additive inductive voltages on the BS 7671 Section 443 establishes that protection energy withstand (e.g. Iimp) (Fig 16A.5). services or to commercial/industrial activity board after the meter) (534.2.1) to divert high energy lightning currents to SPD's connecting leads Power against transient overvoltages is required in an The risk of consequential loss (to life, Section 443 states that 'transient overvoltages The lower the voltage protection level (Up), always results in the need to install earth, followed by downstream SPDs at Ground Ground Ground Ground installation which includes a structural lightning property or provision of service) is transmitted by the supply distribution system As close as practicable to sensitive the better the protection afforded to the Reducing risk of downstream voltage Level Level Level Level protection measures (443.2.4 Note 2). appropriate points to protect sensitive and protection system (LPS), and/or connected deemed unacceptable (443.2.4) are not significantly attenuated downstream equipment (sub-distribution level), withstand voltage or impulse immunity of oscillations which can reach up to twice SPD selection notes critical equipment. Power Power Power metallic service lines at risk from lightning. Following this process, where the need for in most installations' (443.1.1 NOTE 3). and local to critical equipment (534.2.1) the equipment (534.2.3.1.1). the SPD's U and cause damage at Data LPL refers to Lightning If terminal equipment to Category I of Table p Telecom protection is established, BS 7671 requires equipment (534.2.3.1.2) Unknown Protection Level, as defined It details protection requirements for 44.3, such as computers/laptops etc., is to be Equally, short connecting leads between Water the selection and installation of SPDs on Gas { by BS EN/IEC 62305. AC power lines, and refers to BS EN 62305 connected to the fixed electrical installation, Service entrance/ Sub-distribution board Terminal equipment the SPD and conductors are paramount to Furse SPDs are designed with industry leading the AC power supply in accordance with regarding additional metallic service lines (data, it must be protected against transient Main distribution board Line Line keep transient overvoltages to a minimum low voltage protection levels (Up), and many Voltage protection level (Up) its Section 534. length length at the equipment terminals signal & telecoms). overvoltages (Table 44.4). > 10 m > 10 m (see Figure 6). include a remote display option to ensure SPD OCPD L1 L1 positioning as close as possible to conductors. should be lower than the withstand voltage of L2 L2 OCPD START sensitive equipment (1.5 kV L3 L3 Category I) or the impulse 3 Phase 400 V immunity of critical Risk of direct lightning YES N N < 0.25 m equipment (approx. 715 V (BS EN 62305) or lightning protection PEN PE OCPD Service entrance, system installed? (443.1.1) after electricity for 230/400 V supplies) (534.2.3.1). SPD meter (Main NO LL1 N N1 distribution PATENT 125 AgL Type 3 SPD performance APPLIED FOR ESP 240D1 STATUS INDICATION ESP 415 D1 Seriesor ESP 415 M1 Series ESP 415/III/TNSor ESP 415 M2 Series ESP 415 D1 Series or ESP 415 M1 Series For LPL I & II or For LPL III & IV L N T1 Iimp 4kA B board (MDB) In 20kA Uc 280Vac 47-63Hz GREEN FULL PROTECTION T2 Imax 40kA C applies at equipment GREEN & RED REDUCED PROTECTION EN/IEC 61643 T3 Uoc 6kV D OCPD OCPD (replace unit) (for electronics ESP 415/I/TNS ESP 415/III/TNS Install lightning current TYPE 1 SPD REDNO PROTECTION WARNING: If lit / flashing disconnect ! ALTERNATIVE unit & check Neutral Overhead line supplying the to Earth voltage YES Risk of located near or or terminals. To BS EN 62305 an or combined TYPE 1+2 SPD on main STATUSSTATUS 11 building at risk of direct strike - switching 14 12 SPD's voltage protection level distribution board to prevent transient MDB before SDB) ESP 415 M4 ESP 415 M2 simplified risk see BS EN 62305 (443.1.1) (Up) should be no more than L L' L2 L2' L3 L3' N N' (for electronics (for electronics assessment dangerous flashover (534.2.1) L1 L2 L3 N Main earthing 250 AgL If RED replace located near 600 V when tested to PATENT located near APPLIED terminal or < 0.25 m (443.2.4). NO FOR ESP 415/I/TNS Enhanced connecting MDB before SDB) MDB before SDB) BS EN 61643-11 Class III test. Enhanced Mains Protector Mains EN/IEC 61643 Protector conductor bar limp = 25kA/mode lmax = 100kA/mode ln = 25kA/mode All the Furse Combined Type Uc = 320VAC Up < 1.4kV Installation presents higher risk Ures(limp) < 1.3kV PE 1+2+3 & Type 2+3 SPDs Protection against transient STATUS 11 (e.g. fire) or requires higher reliability 14 12 Consider following NO Figure 6: Critical length of connecting conductors (534.2.9) shown in the selection chart from transient overvoltages, overvoltages not required 3 Phase 400 V levels of consequences ESP 415/I/TNS ESP 415 D1/LCD Full Mode Fixed equipment Critical equipment meet this requirement. (443.2.1, 443.2.2) if equipment from transient including electrical switching Type 1+2 SPD Type 1+2+3 SPD (e.g. UPS) (e.g. hospital SPD connections should be kept as short as possible ideally below 0.25 m between SPD, live conductors & earth, 1 Phase 230 V withstand voltage1 to Table 44.3 equipment) All Furse SPDs shown have overvoltages, including (443.2.2 Note) - see BS EN 62305 but in any case not more than 0.5 m, to reduce risk of additive inductive voltage drops across the conductors. Sub‐distribution been tested to at least the electric switching YES Main earthing terminal board (SDB) ‐ For 3 Phase 400 V: For 1 Phase 230 V: minimum nominal discharge Install coordinated set of or or SPD coordination Protect additional metallic services located ESP 415 D1 Series, or ESP 240 D1 Series, or current (I ) of 5 kA 8/20 transient overvoltage SPDs for ESP 415/I/TNS with Type 1 OCPD : Overcurrent protective device (fuse) ESP 415 D1/LCD with Type 2 Combined Type 2+3 Plug-in ESP MC with Type 3 ❱ ❱ nspd performance installed at performance installed at sub- performance of the SPD performance protects critical > 10 m from ESP 415 M1 Series ESP 240 M1 Series waveform, for TN-S or Consequences related to equipment protection (e.g. TYPE 2 service entrance to divert distribution protects fixed installed at sub-distribution equipment at local level Smaller installations may require only BS 7671 is focused towards protection YES MDB feeding TN-C-S supplies as specified human life, e.g. safety/medical or Combined TYPE 2+3) high energy lightning equipment on the electrical protects downstream against switching transients. a single SPD (534.2.2). of AC power supplies. electronic currents to earth, and installation against transient sensitive equipment against by BS 7671 (534.2.3.4.1). equipment? (443.2.4) on distribution boards feeding remove risk of flashover. overvoltages. transient overvoltages. equipment However where the protective distance For protection measures against direct Note: I as defined by sensitive electronic nspd between SPD and electrical equipment lightning strikes, and against transient BS 7671 correlates with I of NO equipment (534.2.6) Figure 5: Typical installation on a 230/400 V TN-C-S/TN-S system using Furse SPDs, to meet the requirements of BS 7671 n exceeds 10 m, additional downstream SPDs overvoltages on additional metallic service BS EN/IEC 61643. may be needed to counter voltage oscillations lines (e.g. data, signal & telecoms), BS 7671 Critical terminal Consequences related to loss of Where a service entrance YES Selecting appropriate SPDs Transient overvoltage SPDs (Type 2 and Type 3, These SPDs, classed as enhanced SPDs to equipment ‐ ESP MC public service, e.g. IT centres ❱ (534.2.3.1.1). refers to BS EN 62305 (534.1 NOTE 2). Type 1 SPD is required, it or Combined Type 1+2+3 and Type 2+3) BS EN 62305, offer technical and economic located > 10 m ESP MC/TN/RJ11 (e.g. for fax machines) and museums? (443.2.4) SPDs are classified by Type within SPDs installed on the same conductor should Full protection of electronic systems can only from SDB ESP MC/Cat‐5e (e.g. for servers) should be tested to Check if data, signal should therefore be installed downstream of advantages over standard SPDs, providing: BS 7671 (534.2.1), following the criteria coordinate with each other to ensure effective, be achieved if all incoming/outgoing metallic withstand lightning impulse NO and telecoms lines the service entrance. established in BS EN/IEC 62305. Combined equipotential bonding and continuous protection (534.2.1 & 534.2.3.6). services, including data, signal and telecoms currents (Iimp) to require protection These SPDs further protect against those transient overvoltage protection lines are protected. BS EN/IEC 61643. Consequences related to loss Where a building includes a structural LPS, or The selection chart (right) defines the appropriate YES (443.1, 534.2.1) transient overvoltages caused by indirect (Type 1+2 & Type 1+2+3) Standard Remote Display Weatherproof Status of commercial activity, e.g. connected overhead metallic services at risk Furse SPDs to achieve coordination on a SPD Performance 1 Remote displays enable positioning of an SPD The value of Iimp for an lightning (via resistive or inductive coupling) Part No. Option Part No.1 enclosure2 indication installation should be hotels, banks, farms? (443.2.4) from a direct lightning strike, equipotential Full mode (common and differential mode) 230/400 V TN-S or TN-C-S system, dependent close to conductors with the display mounted in and electrical switching of inductive loads. calculated according to bonding SPDs (Type 1 or Combined Type 1+2) protection, essential to safeguard sensitive on installation requirement, in line with BS 7671. ESP 415/I/TNS - WBX D4 Combined Type 1+2 LED an easily visible position. Data/ WBX D4 BS EN 62305. Where it NO must be installed at the service entrance, to Combined Type SPDs (such as the Furse electronic equipment from all types of Telecom ESP 415/III/TNS - Combined Type 1+2 LED 2 For TT systems, contact Furse. Weatherproof enclosures are rated to IP65 or cannot be calculated, the remove risk of flashover (534.2.3.4.2). ESP D1 Series and ESP M1/M2/M4 Series) transient overvoltage - lightning & ESP 415 M4 ESP 415 M4R WBX M4 Combined Type 1+2+3 LED above and enable mounting of SPDs in adverse SPD should have capability Consequences related to All Furse SPD sets for power and data lines are Power ESP 415 M2 ESP 415 M2R WBX M2 Combined Type 1+2+3 LED YES Protection against transient significantly simplify the SPD selection process, switching (524.2.2 NOTE 1), and environments. They should be used where the individuals or groups, e.g. Installation of Type 1 SPDs alone however specifically designed to ensure coordination. ESP 415 D1 ESP 415 D1R WBX D8 Combined Type 1+2+3 LED not less than 12.5 kA per overvoltages not required if equipment whether installing at the service entrance or SPD is not mounted within a distribution board. 1 does not provide protection to electronic Effective SPD coordination within a single WBX D8 Combined Type 1+2+3 LCD3 mode to PE or common residential buildings? (443.2.4) withstand voltage to Table 44.3 downstream in the electrical system. Following BS 7671, installation of Furse SPDs ESP 415 D1/LCD ESP 415 D1R/LCD systems (534.2.1 NOTE 3). unit versus installation of multiple standard WBX 4 Combined Type 1+2+3 LED 3 LCD remote display includes rotating screen text mode (534.2.3.4.2). at service entrance, sub-distribution and at ESP 415 M1 ESP 415 M1R Type SPDs to protect terminal equipment ESP 240 D1 - WBX D4 Combined Type 1+2+3 LED (by 90˚) for optimal positioning and viewing, as For more information on SPD Figure 4: Transient overvoltage risk assessment to BS 7671 critical electrical equipment, will ensure IMPORTANT: Equipment is ONLY protected against ESP 240 M1 - WBX 3 Combined Type 1+2+3 LED well as audible status warning. selection, contact Furse. optimal, consistent protection against transient overvoltages if all incoming / outgoing ESP MC - - Combined Type 2+3 LED 1 Note, withstand voltage protects only against failure of equipment. For continuous operation of critical equipment, impulse immunity must be protected. transient overvoltages. mains and data lines have protection fitted. Transient overvoltage (surge) protection
UK OFFICE MIDDLE EAST OFFICE
Thomas & Betts Limited Thomas & Betts Ltd. Br. Furse Office 724 6WA West Wing Wilford Road Dubai Airport Free Zone Nottingham PO Box 54567 NG2 1EB Dubai United Kingdom United Arab Emirates ❱ Amendment 1 of BS 7671 places a clear The latest amendment to the IET ❱ Why is transient overvoltage protection Degradation of electronic systems, however, responsibility for transient overvoltage Switchboard +44 (0)115 964 3700 Tel +971 (0)4 609 1635 Wiring Regulations 17th Edition so important? begins at much lower overvoltage levels and protection on electrical system designers (BS 7671) brings into sharp focus the can cause data losses, intermittent outages Transient overvoltages are short duration and installers. Fax +44 (0)115 986 0538 Fax +971 (0)4 609 1636 need to protect sensitive and critical and shorter equipment lifetimes (see Figure 3). surges in voltage between two or more electronic systems against transient For many in this sphere of work, assessing the Sales tel +44 (0)115 964 3800 conductors (L-PE, L-N or N-PE), which can Where continuous operation of electronic overvoltages (surges). need for transient overvoltage protection will Sales fax +44 (0)115 986 0071 [email protected] reach up to 6 kV on 230 Vac power lines, systems is critical, for example in hospitals, be a new requirement. Amendment 1 of BS 7671, effective from and generally result from: banking and most public services, degradation must be avoided by ensuring these transient Defining when and where to install SPDs can 1st January 2012, requires all electrical Atmospheric origin (lightning activity) [email protected] overvoltages, which occur between L-N, are be a complex process, and sourcing the right system designs and installations to be through resistive or inductive coupling SOUTH EAST ASIA OFFICE limited below the impulse immunity of expertise can often be as important as www.furse.com assessed against risk of transient overvoltages (see Figures 1 & 2), and/or of atmospheric origin, or from switching equipment. This can be calculated as twice specifying the right product. Electrical switching of inductive loads Thomas & Betts events, in line with its Sections 443 & 534. the peak operating voltage of the electrical That’s why we support our transient Asia (Singapore) Pte Ltd Transient overvoltages significantly damage system, if unknown (i.e. approximately 715 V Section 443 defines the criteria for risk overvoltage solutions with EUROPEAN HEADQUARTERS and degrade electronic systems. for 230 V systems). CPD-accredited seminars 10 Ang Mo Kio Street 65 assessment, whereas Section 534 describes Outright damage to sensitive electronic Protection against transient overvoltages and training, including: #06-07 Techpoint the selection and installation of suitable Surge Thomas & Betts Protective Devices (SPDs), where required, for systems, such as computers etc, occurs when can be achieved through installation of a Transient overvoltage protection Transient overvoltage protection Seminars are conducted at customer premises European Centre SA Singapore 569059 effective transient overvoltage protection. transient overvoltages between L-PE or N-PE coordinated set of SPDs at appropriate points to BS 7671 to BS EN 62305 or at our head office in Nottingham, UK. BSI ™ exceed the withstand voltage of the electrical in the electrical system, in line with BS 7671 Whilst concerned with protection of AC 200 Chaussée de Waterloo equipment (i.e. above 1.5 kV for Category I Section 534 and the guidance provided in Providing key guidance on the risk Detailing the protection requirements To arrange a seminar, or for more information Tel +65 6720 8828 power supplies, BS 7671 does make clear equipment to BS 7671 Tables 44.3 & 44.4). this publication. assessment principles defined within for electrical and electronic systems on protecting your installations against B-1640 Rhode-St-Genèse UKAS QUALITY the need to protect all incoming/outgoing Fax +65 6720 8780 MANAGEMENT Section 443, plus selection and installation within structures, in accordance with transient overvoltages, contact us directly on: Equipment damage leads to unexpected Selecting SPDs with lower (i.e. better) voltage Belgium 003 metallic service lines, including data, signal of SPDs in line with Section 534 of BS EN 62305-4, including the lightning and telecoms lines, following BS EN 62305. failures and expensive downtime, or risk of protection levels (Up) is a critical factor, BS 7671:2008 (+A1:2011). protection zone (LPZ) concept, and the [email protected] Q06054 fire/electric shock due to flashover, if especially where continuous usage of application and coordination of SPDs. +44 (0)115 964 3700 Tel +32 (0)2 359 8200 insulation breaks down. electronic equipment is essential. e-mail: [email protected] Fax +32 (0)2 359 8201
DAMAGE DAMAGE > 1.5 kV Degradation (L-PE/N-PE)
Safe Operating Area Degradation > 2x peak operating voltage (e.g. 715 V L-N)
Safe Operating Area www.tnb-europe.com Nominal Transient overvoltage protection Degradation system voltage (e.g. 230 V) DAMAGE to IET Wiring Regulations 17th Edition (BS 7671:2008+A1:2011) Figure 1: Resistive coupling Figure 2: Inductive coupling Figure 3: Equipment risk Resistively coupled transients are caused by differences Inductively coupled transients are caused by Degradation of electronic systems begins at lower The content of this Thomas & Betts publication has been carefully checked for accuracy at the time of print. However, Thomas & Betts in potential between two connected earths. electromagnetic pick-up. transient overvoltage levels and affects critical doesn’t give any warranty of any kind, express or implied, in this respect and shall not be liable for any loss or damage that may result electronic systems whenever the impulse immunity from any use or as a consequence of any inaccuracies in or any omissions from the information which it may contain. E&OE. Energy from ground strikes flows away through the A lightning discharge gives rise to an of the equipment is compromised. Copyright Thomas & Betts Corp. 2012. Copyright in these pages is owned by Thomas & Betts except where otherwise indicated. No part of path of least resistance, and increases the potential in electromagnetic field. If metallic services, such this publication may be reproduced, copied or transmitted in any form or by any means, without our prior written permission. Images, local earths, cabling and electronic circuitry. as overhead power lines, pass through this Damage occurs when a transient overvoltage trade marks, brands, designs and technology are also protected by other intellectual property rights and may not be reproduced or field a voltage will be picked up by, or induced exceeds the withstand voltage of electrical and appropriated in any manner without written permission of their respective owners. Thomas & Betts reserves the right to change and Where these are linked to separate earths by a metallic on to, the line. electronic equipment. improve any product specifications or other mentions in the publication at its own discretion and at any time. These conditions of use are service line, the potential is shared, creating transient governed by the laws of the Netherlands and the courts of Amsterdam shall have exclusive jurisdiction in any dispute. overvoltages as the current attempts to flow.
ESP-BS7671-0612 Transient overvoltage (surge) protection
UK OFFICE MIDDLE EAST OFFICE
Thomas & Betts Limited Thomas & Betts Ltd. Br. Furse Office 724 6WA West Wing Wilford Road Dubai Airport Free Zone Nottingham PO Box 54567 NG2 1EB Dubai United Kingdom United Arab Emirates ❱ Amendment 1 of BS 7671 places a clear The latest amendment to the IET ❱ Why is transient overvoltage protection Degradation of electronic systems, however, responsibility for transient overvoltage Switchboard +44 (0)115 964 3700 Tel +971 (0)4 609 1635 Wiring Regulations 17th Edition so important? begins at much lower overvoltage levels and protection on electrical system designers (BS 7671) brings into sharp focus the can cause data losses, intermittent outages Transient overvoltages are short duration and installers. Fax +44 (0)115 986 0538 Fax +971 (0)4 609 1636 need to protect sensitive and critical and shorter equipment lifetimes (see Figure 3). surges in voltage between two or more electronic systems against transient For many in this sphere of work, assessing the Sales tel +44 (0)115 964 3800 conductors (L-PE, L-N or N-PE), which can Where continuous operation of electronic overvoltages (surges). need for transient overvoltage protection will Sales fax +44 (0)115 986 0071 [email protected] reach up to 6 kV on 230 Vac power lines, systems is critical, for example in hospitals, be a new requirement. Amendment 1 of BS 7671, effective from and generally result from: banking and most public services, degradation must be avoided by ensuring these transient Defining when and where to install SPDs can 1st January 2012, requires all electrical Atmospheric origin (lightning activity) [email protected] overvoltages, which occur between L-N, are be a complex process, and sourcing the right system designs and installations to be through resistive or inductive coupling SOUTH EAST ASIA OFFICE limited below the impulse immunity of expertise can often be as important as www.furse.com assessed against risk of transient overvoltages (see Figures 1 & 2), and/or of atmospheric origin, or from switching equipment. This can be calculated as twice specifying the right product. Electrical switching of inductive loads Thomas & Betts events, in line with its Sections 443 & 534. the peak operating voltage of the electrical That’s why we support our transient Asia (Singapore) Pte Ltd Transient overvoltages significantly damage system, if unknown (i.e. approximately 715 V Section 443 defines the criteria for risk overvoltage solutions with EUROPEAN HEADQUARTERS and degrade electronic systems. for 230 V systems). CPD-accredited seminars 10 Ang Mo Kio Street 65 assessment, whereas Section 534 describes Outright damage to sensitive electronic Protection against transient overvoltages and training, including: #06-07 Techpoint the selection and installation of suitable Surge Thomas & Betts Protective Devices (SPDs), where required, for systems, such as computers etc, occurs when can be achieved through installation of a Transient overvoltage protection Transient overvoltage protection Seminars are conducted at customer premises European Centre SA Singapore 569059 effective transient overvoltage protection. transient overvoltages between L-PE or N-PE coordinated set of SPDs at appropriate points to BS 7671 to BS EN 62305 or at our head office in Nottingham, UK. BSI ™ exceed the withstand voltage of the electrical in the electrical system, in line with BS 7671 Whilst concerned with protection of AC 200 Chaussée de Waterloo equipment (i.e. above 1.5 kV for Category I Section 534 and the guidance provided in Providing key guidance on the risk Detailing the protection requirements To arrange a seminar, or for more information Tel +65 6720 8828 power supplies, BS 7671 does make clear equipment to BS 7671 Tables 44.3 & 44.4). this publication. assessment principles defined within for electrical and electronic systems on protecting your installations against B-1640 Rhode-St-Genèse UKAS QUALITY the need to protect all incoming/outgoing Fax +65 6720 8780 MANAGEMENT Section 443, plus selection and installation within structures, in accordance with transient overvoltages, contact us directly on: Equipment damage leads to unexpected Selecting SPDs with lower (i.e. better) voltage Belgium 003 metallic service lines, including data, signal of SPDs in line with Section 534 of BS EN 62305-4, including the lightning and telecoms lines, following BS EN 62305. failures and expensive downtime, or risk of protection levels (Up) is a critical factor, BS 7671:2008 (+A1:2011). protection zone (LPZ) concept, and the [email protected] Q06054 fire/electric shock due to flashover, if especially where continuous usage of application and coordination of SPDs. +44 (0)115 964 3700 Tel +32 (0)2 359 8200 insulation breaks down. electronic equipment is essential. e-mail: [email protected] Fax +32 (0)2 359 8201
DAMAGE DAMAGE > 1.5 kV Degradation (L-PE/N-PE)
Safe Operating Area Degradation > 2x peak operating voltage (e.g. 715 V L-N)
Safe Operating Area www.tnb-europe.com Nominal Transient overvoltage protection Degradation system voltage (e.g. 230 V) DAMAGE to IET Wiring Regulations 17th Edition (BS 7671:2008+A1:2011) Figure 1: Resistive coupling Figure 2: Inductive coupling Figure 3: Equipment risk Resistively coupled transients are caused by differences Inductively coupled transients are caused by Degradation of electronic systems begins at lower The content of this Thomas & Betts publication has been carefully checked for accuracy at the time of print. However, Thomas & Betts in potential between two connected earths. electromagnetic pick-up. transient overvoltage levels and affects critical doesn’t give any warranty of any kind, express or implied, in this respect and shall not be liable for any loss or damage that may result electronic systems whenever the impulse immunity from any use or as a consequence of any inaccuracies in or any omissions from the information which it may contain. E&OE. Energy from ground strikes flows away through the A lightning discharge gives rise to an of the equipment is compromised. Copyright Thomas & Betts Corp. 2012. Copyright in these pages is owned by Thomas & Betts except where otherwise indicated. No part of path of least resistance, and increases the potential in electromagnetic field. If metallic services, such this publication may be reproduced, copied or transmitted in any form or by any means, without our prior written permission. Images, local earths, cabling and electronic circuitry. as overhead power lines, pass through this Damage occurs when a transient overvoltage trade marks, brands, designs and technology are also protected by other intellectual property rights and may not be reproduced or field a voltage will be picked up by, or induced exceeds the withstand voltage of electrical and appropriated in any manner without written permission of their respective owners. Thomas & Betts reserves the right to change and Where these are linked to separate earths by a metallic on to, the line. electronic equipment. improve any product specifications or other mentions in the publication at its own discretion and at any time. These conditions of use are service line, the potential is shared, creating transient governed by the laws of the Netherlands and the courts of Amsterdam shall have exclusive jurisdiction in any dispute. overvoltages as the current attempts to flow.
ESP-BS7671-0612