# 277V breakers for 50 hertz?



## 10492 (Jan 4, 2010)

Don't really understand this one.

60Hz 208 panel had standard 240V rated BL breakers..
50Hz 208 panel had 480V panel, with 277V rated BQ..


Is a BQ rated 50 hz, and BL not?

Same voltage.


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## Tom45acp (Sep 6, 2011)

I looked in UL's Marking Guide for Molded Case Circuit Breakers. Here's what it says " For ac voltage ratings other than 60 Hz, the frequency is marked." That indicates to me that if the breaker is not marked 50 Hz, then it would be a listing violation to use it on a 50 Hz system.


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