presented by telematic ltd applications of surge protection devices introduction
TRANSCRIPT
Charge accumulation within cloud
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Negative charged cloud base
Updraughts of warm air
Down draughts of
cold air
Surface rain
Lightning’s annual cost (USA)
Economic$139 Million property damage in
USA$40 Million claims to Factory Mutual
PersonalAverage 70 fatalities
Less obvious cost of strikes
Surges also cause:
System down time
Lost business opportunities
System unreliability
Lightning Strike to Building
200KA
High local potential
Little or no damage occurs to sub-systems within structure
Resistive Coupling into Cabled System
200KA
Remote ‘ground’
High local potential
High potential
across insulation
Standards for Surge Protection
IEC 1000-4-5
European std for transients
FCC Part 68, Bellcore TR-NWT-001089
US Telecommunications
BS6651:1992 Appendix C
recommendations in UK
IEEE/C62.41:1991 , REA PE-60, UL1449
AC power SPD test standards
Sources of Transients
Lightning
Static discharges
Switching transients
Power cable induction
Nuclear Electro Magnetic Pulse
Comparison of Transient Sources
Source Field Density Rise Time
Lightning 3V/m 600V/µs@10km
Static discharge 20kV 2kV/ns at impact
NEMP 50 kV/m 5kV/ns @500km
SPDs act by:
Diverting surge current to earth
Clamping output voltage to a safe level
Does NOT prevent lightning but protects against effects
Surge Protection Devices
Standards for Surge Protection
IEC 1000-4-5
European std for transients
BS6651:1992 Appendix C
recommendations in UK
IEEE/C62.41:1991 , REA PE-60, UL1449
AC power SPD test standards
SPDs in Zone 0 - IEC 60079-14
• Why install SPDs?– High likelihood of lightning induced
transients
– Combustible gases present
– Uncontrolled flashover may cause ignition
Zone 0 Protection - IEC 60079-14
Installation Must be installed in Zone 1
Must be close to Zone 0
Must withstand 10kA 8/20µs test to IEC 60-1
IS Applications
Simple Apparatus Non-energy storing
non-voltage producing
Certified Gives greater confidence
IEEE C62.41 summary
IEEE C62.41Gives recommendations only
Splits installations into Categories
Lots of real-world data
IEEE C62.41-1991
Impulse
Service Entrance Category C3
PanelboardCategory B3
Branch Panel Category A1
10kV(1.2,50µs) 6kV(1.2,50µs)
10kA(8/20µs) 3kA(8/20µs)
Ringwave
6kV/500A 100kHz 6kV/500A 100kHz
IEEE C37.90 summary
IEEE C37.90 Standard Surge Withstand Capability (SWC)
Tests for Protective Relays and Relay Systems
Applies to a system and not individual components
SPDs will help comply to the standard
IEC 1000-4-5 summary
IEC 1000-4-5 (801-5) Testing and measurement techniques - Surge
immunity test
Direct lightning is not considered in this standard
Highest test level specified is 4kV
BS 6651 summary
BS 6651 Protection of structures against lightning
Appendix C covers protection of electronic equipment
Gives advice on how to assess lightning risk for an installation the level of protection required
Varistors (MOV)
Multiple current paths
Power absorption
throughout pellet volume
Metal oxide particles
Device SpeedSensitivity 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 Poor
Relays V Slow Good Medium Good
Fuses Slow Fair Medium Good
Comparison of Protection Components
Terminology - SPD basics
SPD basicsLet-through or limiting
voltage
Working voltage
Maximum leakage current
Surge Protector Applications - Selected by Voltage
Thermocouples mV
RTDs <2V
RS422 <12V
Loadcells <30V
RS232 <25V
Switches 24V,110Vac
Process control loops (4/20mA) 24V/48V
Ultra-sonic level transducers 100V
Surge Protector Applications - Typical solutions
Thermocouples SD07X, TP48
RTDs SD07X, TP48
RS422 SD16R
Loadcells LC30
RS232 SD16X, SD32X
Switches PC30/D,SD150X
Process control loops (4/20mA) SD32X, TP48
Ultra-sonic level transducers CA350
SD series circuit
1
2
3
4
5
6
Replaceable fuse module
or loop disconnectMinimal series
resistance
Automatic grounding via DIN-rail
Two lines plus shield
SD vs terminal protectors
Hybrid SPD Shield termination point Automatic grounding Series fusing Line disconnect All in 7mm width
Single component protection No shield termination point Manual grounding per terminal Additional series fusing Additional line disconnect 12-15mm width/loop
plus fuse terminal
plus knife-edge terminal
Surge Protection of Weighing System
Junction box
Oil storage tanks
Load cells
Controlcomputer
Weigh bridge
LC30
LC30
4-wire Bridge / 4-wire Line
Supply
Sense
Signal /
4-Wire Field Cable4-Wire Field Cable
CompensatedLoad Cell
CompensatedLoad Cell
LC30
Metal Weighbridge Bonding
Bond Effective system earth Surge protection device
Summation box
To indicator
Building Protection
Data
Cable
Telephone
Cable
1a. SPD on Main Electrical Distribution Board
1c. SPD on sub-distribution boards feeding critical areas
3. SPD on inter-building Data Cables
2. SPD on External Telephone Lines
Main
ComputerSPD SPD
SPDSPDTelephone
Exchange
Mains Power
Cable
Communications links between buildings
Damage caused by surge on
communications link cable
Remote earth
Local AC supply
Local AC supply
Network running through Different Building Areas
1
2
Industrial area within building
High transientovervoltage
generated by heavymachinery,
welding equipment& power cables
Office area
NP
NP
Typical industrial network Applications
RS232
SD16X, SD16
DP16/D, DP16
RS423
SD16R, SD16X
PC16/D, PC16
RS422 / RS485
SD16/R, SD16X
NP16/S
Common industrial bus systems
Allen Bradley data highway plus PC16/D, SD32R
Foundation Fieldbus SD32R, SD55R
HART SD32X, SD32
Honeywell DE SD32X, DP30/D
Interbus SD32R, NP16/S
Modbus SD32R, NP16/S
Profibus SD32R, NP16/S
WorldFIP SD32R, NP16/S
Typical PSTN Applications
UK jack and socket - office
DP200/4/I
Krone strip - exchange
PX200/10
Telemetry outstation
DP200/D
mSAPN
Typical Private Wire Applications
Krone strip - exchange
DP16/PX
Telemetry outstation
SD16X
DP16/D
mSA16
AC Power Line Protection
Power cables transient sources
Lightning
Load switching
Welding equipment
Elevators/lifts
Applicable standards
IEEE Std. 587-1980 (obsolete)
ANSI/IEEE C62.41 1991
IEC 801-4, -5
MA05, MA10 applications
MA05/D, MA10/D
PLC power supply
Instrument PSU
MA05/SC, MA10/SC
Fire/burglar alarm panel
Computer PSU
MA05/I, MA10/I
Fax Machine
Computer
Grounding for Lightning Protection - Principles
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 common-
mode voltage
Different types of Earth
Mains Protective Earth Essential for personnel safety
Carries leakage currents
Surge Protective Earth Must be able to carry huge currents
Low voltage drop
Instrument or Computer Earth Needs to be kept from ‘dirty’ earth
Conclusion
Protect equipment;-
Exposed to lightning surges & other transients
With difficult or remote access for maintenance
Critical to plant operation & control
Critec AC power products
SRF Range
High current surge protection and filtering (50 - 120kA)
Recommend MA230, MA103 or MA2003
MT Range
Two terminal device containing 5 MOVs (40 - 120kA)
Recommend MA230, MA103 or MA2003
MPM Range
Box containing three MT units (50kA L-N)
Recommend MA230, MA103 or MA2003
Critec LAN protectors
LAN-TYPE-1E
Token Ring protector
Recommend NP08/2R
LAN-TW280
TwinAx protector
Recommend NP16/T
LAN-BNC
Thin Ethernet
Recommend NP08/B
LAN-N
Thick Ethernet
Recommend NP08/N