basilasq
Electrical
- Jul 8, 2011
- 12
We have a substation DC loads supplied via a 250 VDC system. The charger float voltage is actually 270-280 VDC. The question that came up was that all the standard breakers are rated for 250 VDC, and none of the application engineers from Schneider, Eaton, ABB etc. are willing to state that the breakers can operate at the float voltage which is about 10% over the nominal rating. The other option is to spec 600V breakers which is impractical for the whole system given the amount of DC branches and loads.
Is there an overload rating of the breakers at a lower kA value that they are able to operate?
Is there an overload rating of the breakers at a lower kA value that they are able to operate?