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What does backfed mean in conjunction with a circuit breaker and how is this installed?

Issue:
Application

Product Line:
Panelboards

Environment:

UL 67, UL 50, CSA C22.2 No.'s 20-M1989 & 94-M91, NEMA PB1, NFPA 70 Art. 408, Federal Specification W-P-115C Type 1 Class 1 , 2003 IBC, NFPA 5000, ASCE/SE17


Cause:
Unfamiliarity with specialised terminology.

Resolution:

In a panelboard application, a back-fed main breaker is mounted on the branch bus, occupying normal branch breaker mounting space or circuits, instead of in the separate, vertical position more typical of a main breaker. The normal load-side lugs of the back-fed main circuit breaker actually become the (incoming) line lugs of the panelboard, and power flows to the panelboard bussing through the branch connectors of the panelboard interior, to which the back-fed main breaker is connected.


 
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