Old Bus Duct SCCR's
- Thread starter JW9
- Start date
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Senior Member
- Location
- New York, 40.7514,-73.9925
Busway in general usually pretty high, like 65kA or 100kA, but without documentation, it is 5kA
- Location
- Wisconsin
- Occupation
- PE (Retired) - Power Systems
Be careful with really old bus way. Prior to the mid 70s busway was often built with the bars separated from each other over their full length. Unless additional bracing was installed their SCCR was fairly low, probably below 22kA.
Starting in the 70s busway, like Westinghouse Pow-R, is often built with the insulated bars all touching each other, so very high SCCR is easy to achieve.
Didn't the Westinghouse LV busduct go to Cutler Hammer and Eaton?
This is a link to some resources for old stuff.
www.legacyindustrial.com
Starting in the 70s busway, like Westinghouse Pow-R, is often built with the insulated bars all touching each other, so very high SCCR is easy to achieve.
Didn't the Westinghouse LV busduct go to Cutler Hammer and Eaton?
This is a link to some resources for old stuff.
Resources - Legacy Industrial Electric LLC
Data sheets, install manuals, application guides and more for understanding industrial bus duct systems from Legacy Industrial Electric LLC.
www.legacyindustrial.com
Thanks Jim. We do typically default to 22kA, but it would be nice to have some justification/documentation on why that is to provide to the owner. They have 2 of these old armor-clad busway with an available fault current over 22kA, which would be a violation. ABB owns this product line now as far as I can tell. See: https://electrification.us.abb.com/... BuyLog 2019/13_GE Products BuyLog_Busway.pdfBe careful with really old bus way. Prior to the mid 70s busway was often built with the bars separated from each other over their full length. Unless additional bracing was installed their SCCR was fairly low, probably below 22kA.
Starting in the 70s busway, like Westinghouse Pow-R, is often built with the insulated bars all touching each other, so very high SCCR is easy to achieve.
Didn't the Westinghouse LV busduct go to Cutler Hammer and Eaton?
This is a link to some resources for old stuff.
Resources - Legacy Industrial Electric LLC
Data sheets, install manuals, application guides and more for understanding industrial bus duct systems from Legacy Industrial Electric LLC.
- Location
- Wisconsin
- Occupation
- PE (Retired) - Power Systems
In the OP, you said Westinghouse, now you say GE.
Here is a GEP-1100M 0695 catalog page from back in 95.
Here is a GEP-1100M 0695 catalog page from back in 95.
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- Location
- San Francisco Bay Area, CA, USA
- Occupation
- Electrical Engineer
The term "SCCR" is a relatively new phenomenon that became defined in the 2005 NEC, Westinghouse as an electrical company ceased to exist long before that (1994-1996). What you might find from that era is a bus bracing rating or a fault current "withstand" rating. SCCR is kind of a combination of that fault current withstand rating and, if applicable, any interrupt ratings. But since bus duct does not interrupt, the fault current withstand is what we would have used to satisfy 110.10 back in the day.