Siemens Tristar MCC Short Circuit Ratings
Siemens Tristar MCC Short Circuit Ratings
(OP)
Does anyone know where I can find the listed short circuit rating for a Siemens Tristar MCC?
The nameplate on the MCC is listed as having a 65kAIC rating however the breakers in the buckets within the MCC are only rated at 25kA and 35kA depending on the MCC and the breakers that were used.
Is it possible through combination testing to end up with a higher rating of 65kAIC for the MCC even when lower rated breakers are used?





RE: Siemens Tristar MCC Short Circuit Ratings
Technically though, the overall SC rating of the MCC is degraded to the lowest rated individual unit. So if you have one bucket that is only 25kAIC, the entire MCC cannot be connected to a system with higher AFC than that.
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RE: Siemens Tristar MCC Short Circuit Ratings
If there is a main breaker in the MCC and there are series ratings for the main and all of the feeder breakers, it possible the series rating could be 65 kA, but I think this has to be denoted as a series rating.