Applications of Surge Protection Devices Presented by Telematic
Applications of Surge Protection Devices Presented by Telematic Ltd Introduction
Thermionic Valve Technology - Disadvantages
<1000 µJ Thermionic Valve Technology - Advantages
<10 µJ Discrete Transistor Technology
<1 µJ Integrated Circuitry
+ + + Down draughts of cold air _ Updraughts of warm air _ _ _ Negative charged cloud base Surface rain Charge accumulation within cloud
_ _ + ++ Progression of a stepped leader
q Economic l $139 Million property damage in USA l $40 Million claims to Factory Mutual q Personal l Average 70 fatalities Lightning’s annual cost (USA)
n Surges also cause: l System down time l Lost business opportunities l System unreliability Less obvious cost of strikes
Before Day off?
After Permanent retirement !
CAPACITIVE INDUCTIVE RESISTIVE Coupling Mechanisms for Transients
Little or no damage occurs to sub-systems within structure 200 KA High local potential Lightning Strike to Building
200 KA High local potential Remote ‘ground’ High potential across insulation Resistive Coupling into Cabled System
IEC 1000 -4 -5 European std for transients FCC Part 68, Bellcore TR-NWT-001089 US Telecommunications BS 6651: 1992 Appendix C recommendations in UK IEEE/C 62. 41: 1991 , REA PE-60, UL 1449 AC power SPD test standards Standards for Surge Protection
Lightning Static discharges Switching transients Power cable induction Nuclear Electro Magnetic Pulse Sources of Transients
Source Field Density Rise Time Lightning 3 V/m @10 km 600 V/µs Static discharge 20 k. V at impact 2 k. V/ns NEMP 50 k. V/m @500 km 5 k. V/ns Comparison of Transient Sources
SPDs act by: l Diverting surge current to earth l Clamping output voltage to a safe level l Does NOT prevent lightning but protects against effects Surge Protection Devices
IEC 1000 -4 -5 European std for transients BS 6651: 1992 Appendix C recommendations in UK IEEE/C 62. 41: 1991 , REA PE-60, UL 1449 AC power SPD test standards Standards for Surge Protection
I PK (10 KA) 90% 50% 10% 8µs 20µs 8/20µs Short-circuit Current Pulse - IEC 60 -1 t
V PK 90% 50% 1. 2µs 50µs 1. 2/50µs Open-circuit Voltage Pulse t
V PK 90% 50% 10µs 700µs 10/700µs Open-circuit Voltage Pulse t
• Why install SPDs? – High likelihood of lightning induced transients – Combustible gases present – Uncontrolled flashover may cause ignition SPDs in Zone 0 - IEC 60079 -14
n Installation l Must be installed in Zone 1 l Must be close to Zone 0 l Must withstand 10 k. A 8/20µs test to IEC 60 -1 Zone 0 Protection - IEC 60079 -14
n Simple Apparatus l Non-energy storing l non-voltage producing n Certified l Gives greater confidence IS Applications
n IEEE C 62. 41 l Gives recommendations only l Splits installations into Categories l Lots of real-world data IEEE C 62. 41 summary
Service Entrance Category C 3 Panelboard Category B 3 10 k. V(1. 2, 50µs) 6 k. V(1. 2, 50µs) 10 k. A(8/20µs) 3 k. A(8/20µs) Branch Panel Category A 1 Impulse Ringwave 6 k. V/500 A 100 k. Hz IEEE C 62. 41 -1991 6 k. V/500 A 100 k. Hz
Cat A Cat C Cat B IEEE C 62. 41 Locations
IEC 1312 protection zones
n IEEE C 37. 90 l Standard Surge Withstand Capability (SWC) Tests for Protective Relays and Relay Systems l Applies to a system and not individual components l SPDs will help comply to the standard IEEE C 37. 90 summary
n IEC 1000 -4 -5 (801 -5) l Testing and measurement techniques - Surge immunity test l Direct lightning is not considered in this standard l Highest test level specified is 4 k. V IEC 1000 -4 -5 summary
n BS 6651 l Protection of structures against lightning l Appendix C covers protection of electronic equipment l Gives advice on þ how to assess lightning risk for an installation þ the level of protection required BS 6651 summary
+100 MV Lightning as a Capacitor
Incoming cables Local Earth Common mode surges Voltage shift is the same for both cables
Incoming cables Difference mode surges Voltage difference is between cables
Air spark gap Carbon spark gap Gas-filled discharge tube Primary Protection Elements
Spark Gap
1 2 2 -electrode Gas Discharge Tube
1 Electronic Apparatus 2 2 -electrode GDT in 2 -wire loop
1 Electronic Apparatus 2 3 -electrode gas discharge tube
Transient Voltage Surge Suppression Diode Metal Oxide Varistor (MOV) Secondary Protection Elements
Surge Suppression diode 1500 W surge rating Conventional diode 5 W steady state rating Surge Diodes
Metal oxide particles Power absorption throughout pellet volume Multiple current paths Varistors (MOV)
V V MOV I Surge Diode Secondary Element Characteristics I
Device Speed Sensitivity Energy Stability Air Gap Fast Poor High Poor GDT Fast Good High Good Zener V Fast V Good Low Excellent Transorb V Fast Good Medium Excellent Varistors V Fast Poor High Relays V Slow Good Medium Good Fuses Slow Fair Medium Good Poor Comparison of Protection Components
1 2 Conventional Hybrid SPD
1 2 Incoming surge GDT Diode Multi-stage SPD Operation Hybrid
1 2 Hybrid Device with Steering Diodes
1 2 Continuous Overvoltage Suppression
Incoming Surge SPD DC Power Protection of Panel Equipment
Tx Incoming surge Surge diversion Protection of Transmitters
SPDs RF I/O lines Telemetry Equipment AC SPD PSTN Telemetry Outstation
n SPD basics l Let-through or limiting voltage l Working voltage l Maximum leakage current Terminology - SPD basics
Thermocouples m. V RTDs <2 V RS 422 <12 V Loadcells <30 V RS 232 <25 V Switches 24 V, 110 Vac Process control loops (4/20 m. A) 24 V/48 V Ultra-sonic level transducers 100 V Surge Protector Applications - Selected by Voltage
n Networks l Bandwidth l Crosstalk l Insertion loss Terminology - Networks
Thermocouples SD 07 X, TP 48 RTDs SD 07 X, TP 48 RS 422 SD 16 R Loadcells LC 30 RS 232 SD 16 X, SD 32 X Switches PC 30/D, SD 150 X Process control loops (4/20 m. A) SD 32 X, TP 48 Ultra-sonic level transducers CA 350 Surge Protector Applications - Typical solutions
Transmitter protection
Replaceable fuse module or loop disconnect Minimal series resistance 4 1 Two lines plus shield 2 5 3 6 Automatic grounding via DIN-rail SD series circuit
q q q Hybrid SPD Shield termination point Automatic grounding Series fusing Line disconnect All in 7 mm width q q q Single component protection No shield termination point Manual grounding per terminal Additional series fusing Additional line disconnect 12 -15 mm width/loop plus fuse terminal plus knife-edge terminal SD vs terminal protectors
3 -wire transmitter protection
Oil storage tanks Control computer Load cells Weigh bridge LC 30 Junction box Surge Protection of Weighing System LC 30
4 -Wire Field Cable Supply LC 30 Signal / Sense Compensated Load Cell 4 -wire Bridge / 4 -wire Line
Summation box To indicator Bond Effective system earth Surge protection device Metal Weighbridge Bonding
VP 08 - video protection
Monitoring area Field Installation VP 08 installation
Clipit 100
CA 90/CA 350 Aerial protector
SPDs RF I/O lines Telemetry Equipment AC SPD PSTN Telemetry Outstation
SPDs RF I/O lines Telemetry Equipment PSTN RTU Protection
1 c. SPD on subdistribution boards feeding critical areas 1 a. SPD on Main Electrical Distribution Board SPD Main Computer SPD Data Cable 3. SPD on interbuilding Data Cables SPD Telephone Exchange Mains Power SPD Telephone Cable 2. SPD on External Telephone Lines Cable Building Protection
Damage caused by surge on communications link cable Local AC supply Remote earth Communications links between buildings
Outside FL NP NP Building 1 Building 2 Protection for Inter-building Network Link
Industrial area within building Office area 1 NP High transient overvoltage generated by heavy machinery, welding equipment & power cables 2 NP Network running through Different Building Areas
n Signal level n Bandwidth or bits/s n Connector type n In line resistance Network characteristics
n Thin ethernet l NP 08/B n Thick ethernet l NP 08/N n Token Ring l NP 08/2 R Typical LAN Applications
n RS 232 l SD 16 X, SD 16 l DP 16/D, DP 16 n RS 423 l SD 16 R, SD 16 X l PC 16/D, PC 16 n RS 422 / RS 485 l SD 16/R, SD 16 X l NP 16/S Typical industrial network Applications
Allen Bradley data highway plus PC 16/D, SD 32 R Foundation Fieldbus SD 32 R, SD 55 R HART SD 32 X, SD 32 Honeywell DE SD 32 X, DP 30/D Interbus SD 32 R, NP 16/S Modbus SD 32 R, NP 16/S Profibus SD 32 R, NP 16/S World. FIP SD 32 R, NP 16/S Common industrial bus systems
Bus Powered Systems
NP 08/N - Thick ethernet
Thick Ethernet installation
NP 08/B - Thin ethernet
Thin Ethernet installation
Allen Bradley Data Highway Plus
Category 5 installation
PSTN ringing voltage
n UK jack and socket - office l DP 200/4/I n Krone strip - exchange l PX 200/10 n Telemetry outstation l DP 200/D l m. SAPN Typical PSTN Applications
n Krone strip - exchange l DP 16/PX n Telemetry outstation l SD 16 X l DP 16/D l m. SA 16 Typical Private Wire Applications
Earth terminal DP 200/4/I
PSTN connection DP 200/4/I installation
DP 200/D installation
MOV surge clamping
Power cables transient sources Lightning Load switching Welding equipment Elevators/lifts Applicable standards IEEE Std. 587 -1980 (obsolete) ANSI/IEEE C 62. 41 1991 IEC 801 -4, -5 AC Power Line Protection
SPD L N G SPD Protected Load Spur vs Series Connection
Fuse protected network L N G Delta Network of Varistors
Fuses not shown for clarity L 1 L 2 L 3 N G Star-connected Varistors
SPD L N SPD G Fusing AC Power SPDs
n MA 05/D, MA 10/D l PLC power supply l Instrument PSU n MA 05/SC, MA 10/SC l Fire/burglar alarm panel l Computer PSU n MA 05/I, MA 10/I l Fax Machine l Computer MA 05, MA 10 applications
Divert current as soon as possible Use dedicated low impedance connection Make sure other systems are bonded to it, once! Convert series-mode current into commonmode voltage Grounding for Lightning Protection - Principles
Lightning strike to Aeroplane
q Mains Protective Earth l Essential for personnel safety l Carries leakage currents q Surge Protective Earth l Must be able to carry huge currents l Low voltage drop q Instrument or Computer Earth l Needs to be kept from ‘dirty’ earth Different types of Earth
Telecomms Instrumentation Computers Star-connected System Earths
Inductance + Resistance Cable impedance
Recommended earthing philosophy
Incoming Surge SPD DC Power To distribution ground Common Grounding System
Incoming Surge SPD DC Power To distribution ground Preferred Grounding System
Incoming Surge SPD DC Power To distribution ground Disastrous Grounding System
Safe Area Hazardous Area SPD TX SPDs with IS Barriers IS Barrier
SPDs with Zener Barriers
Hazardous Area SPD Safe Area SPD Galvanic Isolator TX SPDs with Galvanic Isolation
Protect equipment; Exposed to lightning surges & other transients With difficult or remote access for maintenance Critical to plant operation & control Conclusion
n n n SRF Range l High current surge protection and filtering (50 - 120 k. A) l Recommend MA 230, MA 103 or MA 2003 MT Range l Two terminal device containing 5 MOVs (40 - 120 k. A) l Recommend MA 230, MA 103 or MA 2003 MPM Range l Box containing three MT units (50 k. A L-N) l Recommend MA 230, MA 103 or MA 2003 Critec AC power products
n n LAN-TYPE-1 E l Token Ring protector l Recommend NP 08/2 R LAN-TW 280 l Twin. Ax protector l Recommend NP 16/T LAN-BNC l Thin Ethernet l Recommend NP 08/B LAN-N l Thick Ethernet l Recommend NP 08/N Critec LAN protectors
n n n LSAC Range l 4 A AC data SPD l Recommend MA 05 or SD 150 X (higher surge rating) LSCP and LSSC Range l High frequency coaxial SPDs l Recommend CA 90 or CA 350 LSJK and LSEK Range l Includes GDT, MOV and surge diode l Recommend SD series Critec data protectors
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