how does open neutral protection in a portable GFI work?

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wireguru

Senior Member
I see a coleman 'quad box' portable GFI with open neutral protection (this is a listed / osha compliant product -not something someone made). When looking at the product, it appears to have a standard GFI receptacle and a duplex receptacle in it. Their literature advertises a '25 amp relay' is in it to provide open neutral protection. I am thinking it has a double pole single throw NO relay inside that has its coil powered from the incoming line before the GFI. The hot and neutral both pass through the relays contacts before the GFI. This way if incoming neutral is lost the GFI never even sees any power?

Am I correct in how this would be set up? Is there more to it besides the relay?
 

76nemo

Senior Member
Location
Ogdensburg, NY
Guess I am just too simple. Yes, that set up would work, but what the heck is the point if the GFCI wouldn't work in an open neutral condition regardless:confused:
 

wireguru

Senior Member
Guess I am just too simple. Yes, that set up would work, but what the heck is the point if the GFCI wouldn't work in an open neutral condition regardless:confused:
ul / nec / osha requires portable GFIs to have open neutral protection. With a standard GFI, if the neutral supplying it is lost the trip mechanism cant work and the gfi and everything downstream will still be hot.
 

76nemo

Senior Member
Location
Ogdensburg, NY
ul / nec / osha requires portable GFIs to have open neutral protection. With a standard GFI, if the neutral supplying it is lost the trip mechanism cant work and the gfi and everything downstream will still be hot.


WOW!!!!!! Learn something new everyday. I never, ever thought of it that way. As soon as a different potential was introduced and the GFCI was grounded, it wouldn't clear the fault???? Is this just for two-wire applications?
 

wireguru

Senior Member
WOW!!!!!! Learn something new everyday. I never, ever thought of it that way. As soon as a different potential was introduced and the GFCI was grounded, it wouldn't clear the fault???? Is this just for two-wire applications?
line and neutral power the trip mechanism in a gfi. lose the neutral, and you have live line side through the gfi and it cant trip
 

76nemo

Senior Member
Location
Ogdensburg, NY
line and neutral power the trip mechanism in a gfi. lose the neutral, and you have live line side through the gfi and it cant trip

Strike that question. I thought about it. Put it down in the books as my stupid question. I know how a GFCI works, but I never thought of it in an open neutral scenario. Thanks for getting my brain back on track.

Call me "Meathead":roll:
 
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