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-   -   Can current backflow through a circuit breaker if volt/amps are applied to the load s (https://www.askmehelpdesk.com/showthread.php?t=550488)

  • Feb 2, 2011, 11:24 AM
    elctricadvise
    Can current backflow through a circuit breaker if volt/amps are applied to the load s
    I was looking to set up a generator circuit in the event of a power outage to keep my sump pump and furnace going. I want to find out, if I manually trip a circuit breaker, can I use the load side of the circuit breaker to continue to power the sump pump and furnace (using the same size wire of course) via the generator without worrying about backfeed through an open breaker? I cannot see any problem with it other than just me having to flip the breaker (which of course it is). The line from the generator does have circuit protection.
  • Feb 2, 2011, 12:17 PM
    jcaron2
    The right way to do this is to install a transfer switch.

    However, to answer your question, yes, a tripped breaker will indeed isolate that circuit from the rest of the panel.
  • Feb 3, 2011, 01:05 PM
    ebaines

    Not an expert on this, but one thought comes to mind - since the circuit breaker only opens the hot lead, I think you need to make sure that the neutral line of the generator output is at the same ground potential as the neutral of the house wiring - otherwise you'd get unwanted current flow through the neutral to ground. Does your generator have this capability?
  • Feb 3, 2011, 03:43 PM
    jcaron2
    Quote:

    Originally Posted by ebaines View Post
    Not an expert on this, but one thought comes to mind - since the circuit breaker only opens teh hot lead, I think you need to make sure that the neutral line of the generator output is at the same ground potential as the neutral of the house wiring - otherwise you'd get unwanted current flow through the neutral to ground. Does your generator have this capability?

    With no connections to the generator, the neutral output floats. Once you hook it to your house's wiring, it will be locked to the same potential as your house's neutral, and no current should flow to ground.

    That does bring up the point, however, that your generator should be well grounded. In theory, hooking it to your house's wiring should ground it, since your house's neutral should be bonded to the ground at the main panel (where the service entrance is). However, the prudent thing to do is to separately ground the generator with its own ground rod.

    Also, by way of disclaimer, bear in mind that I'm not an expert either. Tkrussel is the man for this subject matter.
  • Feb 4, 2011, 08:38 AM
    elctricadvise
    Comment on jcaron2's post
    Thank you and all for your help! I do have the circuit hooked with the generators nuetral to the house nuetral and geneator has its own ground. Thanks Again for your quick responses!

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