2. 2
Surge ArrestersSurge Arresters
Gaps and gaplessGaps and gapless
Silicon Carbide and Metal OxideSilicon Carbide and Metal Oxide
ClassClass
Tests and RatingsTests and Ratings
InstallationInstallation
Field testing and FailuresField testing and Failures
3. 3
Silicon Carbide ArrestersSilicon Carbide Arresters
Blocks cannot conduct continuouslyBlocks cannot conduct continuously
Series gapsSeries gaps
Fast transients cause the series gaps to short over andFast transients cause the series gaps to short over and
insert the silicon carbide blocksinsert the silicon carbide blocks
Gaps must reseal after the arrester operates (gradingGaps must reseal after the arrester operates (grading
circuitry)circuitry)
Duty cycle ratingDuty cycle rating is the maximum 60hz voltage where theis the maximum 60hz voltage where the
gaps can still re-seal against power follow currentgaps can still re-seal against power follow current
Subject to external contaminationSubject to external contamination
Doble study shows that 50% of silicon carbide arrestersDoble study shows that 50% of silicon carbide arresters
tested cannot meet original protection characteristicstested cannot meet original protection characteristics
Problem with moisture contamination and gaps changingProblem with moisture contamination and gaps changing
characteristicscharacteristics
Oldest SiC arresters do not have a pressure relief ratingOldest SiC arresters do not have a pressure relief rating
4. 4
Metal Oxide arrestersMetal Oxide arresters
Station Class Metal Oxide arresters were firstStation Class Metal Oxide arresters were first
introduced around 1980 for transmissionintroduced around 1980 for transmission
applicationsapplications
Originally three varieties:Originally three varieties:
– Gapless – Westinghouse 4” discsGapless – Westinghouse 4” discs
– Shunt gap – General Electric 3” discsShunt gap – General Electric 3” discs
– Series gap – Ohio Brass 3” discsSeries gap – Ohio Brass 3” discs
Today all station class arresters are gaplessToday all station class arresters are gapless
Intermediate and distribution ratings introduced inIntermediate and distribution ratings introduced in
mid 80s (gapless)mid 80s (gapless)
Polymer housings introduced in 90sPolymer housings introduced in 90s
5. 5
Arrester base left on structureArrester base left on structure
after failure.after failure.
9. 9
You have seen in above slides a short introduction about Surge
Arrestor.If you are looking for exporters and suppliers of Surge
Arrestor and its exporters,you feel free to contact with
tradeindia.you can also visit at:
http://www.tradeindia.com/manufacturers/surge-arrestor.html
10. 9
You have seen in above slides a short introduction about Surge
Arrestor.If you are looking for exporters and suppliers of Surge
Arrestor and its exporters,you feel free to contact with
tradeindia.you can also visit at:
http://www.tradeindia.com/manufacturers/surge-arrestor.html