vacuum circuit breaker foreign material
vacuum circuit breaker foreign material
(OP)
Has anyone observed this condition before? We have Siemens vacuum circuit breakers (4160 V and 13800V) but this might not be limited to just these.
When removing from service for a PM, we found some foreign material encircling several of the stabs. The material was black and looked like metal shavings (although not magnetic) and was distributed around the stabs in a concentric circle (almost like it was blown down).
The stabs are coated with a silver alloy and the insulators are made of a proprietary material (so not sure of the exact makeup) that is ceramic like but not completely ceramic. Analysis of the material shows it contains silver, silicon, aluminum, calcium, copper and magnesium with traces of iron, sodium and zinc.
We are ready to cut our monetary losses since supplier is saying it's not their fault but for some extra cash, they will look into it more. I would like to determine some kind of apparent cause to determine if we might experience this again the future. Any experiences or ideas are greatly appreciated!
When removing from service for a PM, we found some foreign material encircling several of the stabs. The material was black and looked like metal shavings (although not magnetic) and was distributed around the stabs in a concentric circle (almost like it was blown down).
The stabs are coated with a silver alloy and the insulators are made of a proprietary material (so not sure of the exact makeup) that is ceramic like but not completely ceramic. Analysis of the material shows it contains silver, silicon, aluminum, calcium, copper and magnesium with traces of iron, sodium and zinc.
We are ready to cut our monetary losses since supplier is saying it's not their fault but for some extra cash, they will look into it more. I would like to determine some kind of apparent cause to determine if we might experience this again the future. Any experiences or ideas are greatly appreciated!






RE: vacuum circuit breaker foreign material
RE: vacuum circuit breaker foreign material
RE: vacuum circuit breaker foreign material
RE: vacuum circuit breaker foreign material
"Our virtues and our failings are inseparable, like force and matter. When they separate, man is no more." Nikola Tesla
Member, P3
jraef (Electrical)
Here is the paper I was thinking of. Excellent photos at the end. ttp://nepp .nasa.gov/ whisker/re ference/te ch_papers/ chudnovsky 2002-paper -silver-co rrosion-wh iskers.pdf
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RE: vacuum circuit breaker foreign material
h
"Our virtues and our failings are inseparable, like force and matter. When they separate, man is no more." Nikola Tesla
Member, P3
Read the Eng-Tips Site Policies at FAQ731-376
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