# Backfeed breaker requirements



## Pharon (Jan 20, 2014)

So 705.12(D)(4) says the following: "Circuit breakers, if backfed, shall be suitable for such operation."

Does anyone know how to identify a breaker suitable for backfed use other than checking the UL Listing from the manufacturer?

I've heard rules like "it can't have an interchangeable trip unit" and "it can't have 'line/load' markings" but have no idea where these requirements (if true) actually come from.


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## bkmichael65 (Mar 25, 2013)

They just can't have line/load markings


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## Dennis Alwon (May 9, 2009)

Standard breaker can be backfed as long as secure it in place with a tie down. Not all panel have this ability but most do and it must be done where the tie down will fit.

The breaker that have lugs on both side must not be marked line and load and then you are good to go.

The only place I find back fed is 408-36(D) and below but that is in 690 for solar--



> Back-Fed Circuit Breakers. Plug-in type back-fed
> circuit breakers connected to a stand-alone or multimode
> inverter output in stand-alone systems shall be secured in
> accordance with 408.36(D). Circuit breakers marked “line”
> and “load” shall not be back-fed.


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## Pharon (Jan 20, 2014)

> Back-Fed Circuit Breakers. Plug-in type back-fed
> circuit breakers connected to a stand-alone or multimode
> inverter output in stand-alone systems shall be secured in
> accordance with 408.36(D). Circuit breakers marked “line”
> and “load” shall not be back-fed.


690.10(E) only applies to stand-alone systems (not connected to utility). Interestingly, that 408.36(D) fastener requirement does not apply to utility-interactive inverters, per 705.12(D)(5).

Also, I found out that these requirements come from the UL 489 Standard for Molded Case Circuit Breakers. To get a molded case breaker UL Listed for reverse-feed applications, it needs to be tested to trip on overcurrent from both directions (per paragraph 7.1.1.18), have markings, or lack thereof, per paragraph 9.1.1.13, and a trip unit that complies with paragraph 6.1.5.12.

Bottom line is that, when in doubt, ask the manufacturer. Eaton has a whole list of their breaker types that are and are not UL Listed for reverse-feed.

Good news is that all low voltage power circuit breakers are suitable for reverse-feed, because it's a mandatory requirement for getting a UL 1066 Standard Listing.


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