Transient Surges and Surge Suppression Technologies Joe Kenney International Business Development...
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Transcript of Transient Surges and Surge Suppression Technologies Joe Kenney International Business Development...
Transient Surges and Surge Suppression Technologies
Joe KenneyInternational Business Development Manager
Caribbean, Latin America and Asia Pacific
Outside & InsideCauses of Transients
Outside Causes
1. Environmental
i.e. Lightning
2. Power Company
i.e. Grid Switching
3. Other Users
Power Quality Decreases as the Number of Other Users Sharing the Power Feed Increases
Inside Causes
1. Internal Power Switching
i.e. Air Conditioning, Refrigeration Systems, Florescent Light Ballasts, Elevators, Co-pay Machines to Coffee Pots, Various Types of Motor Starter Contactors
All Suppressors Should Be Tested with Both Long Waveforms (10/1000 µs) and
Short Waveforms (8/20 µs)
• AC switching transients (10/1000 µs) occur more often than lightning (8/20 µs).
• The suppressor will need to dissipate 50 times more energy in the real world (10/1000 µs) than it will with the 8/20 µs waveform test.
Why?
Test Current Waveforms Comparison(Per IEEE C62.41-1991)
3000
2500
2000
1500
1000
500
010 100 200 300 400 500 600 700 800 1000
8/20 µsec (shortwave)
10/1000 µsec (longwave)
Represents amperage divertedby the SPD in a 8/20 surge
Represents amperage divertedby the SPD in a 10/1000 surge
The SPD will dissipate approximately50 times more power with the 10/1000 than the 8/20 waveform test
Time (µs)
Cur
rent
(I)
IP
Requirements for a Surge Protective Device (SPD)
• Response Time• Voltage Protection Level• Surge Current• Power Dissipation• Disturbance Free Operation• Performance Reliability• Operating Life• Lead Length
Voltage Protection LevelFor 120 VAC Nominal (L-N)
(100 to 132 VAC)
Time (ms)
170
200
300
400
500
0
Failure Level
Degradation, Errors &Possible Damage Level
Protection LevelVol
tage
Power Dissipation ComparisonFor 120 VAC Nominal (L-N)
(100 to 132 VAC)600
400
300
120
Lower voltage limiting suppressormust dissipate the power in areas 1 & 2
Higher voltage limiting suppressor must dissipate the power in area 1
0Time (ms)
Vol
tage
Technology Comparison
Non Degrading
Response Time <5ns
Expected Life
Reliable Performance
Voltage Protection Level
*SASD
Yes
Yes
Long
Yes
<130%
Filter
Yes
Yes
Long
No
Frequency Dependant
MOV
No
No
Degrade w/use
No
> 130%
Gas Tube
No
No
Degrade w/use
No
>130%
* SASD results based on Lattice Matrix or ASAT design technology
• Eliminating transient overvoltages:
– reduces operation costs
– reduces downtime, repair & maintenance costs
• A surge suppressor is not an insurance policy, rather an assurance that your system won’t have problems. Insurance policies cover repair costs after failure, not losses related to downtime which can far exceed repair costs.
• By evaluating overall system cost & investment, it’s clear that transient overvoltage suppression equipment must become an integral part of any electronic system.
Conclusion