GFI plugged in to a GFI

mudcat555

Member
This is the situation. Customer bought exterior sidewalk heating mats. The mats come with a weatherproof GFI built right in to the male cord end. The outside receptacle that they want to plug in to is also a GFI . Can a GFI be fed by a GFI without causing any undesirable effects and nuisance tripping?
 

ActionDave

Moderator
Staff member
You can plug a gfci cord into a gfci recpt and it is going to work just fine. Cheesy 120V hot tubs have the same cord and they get plugged into gfci plugs all the time and work just fine.
 

Dennis Alwon

Moderator
Staff member
There is an exception to 210.8. I wonder if the cord has gfci or gfpe. My guess is it is gfpe

(3) Outdoors
Exception to (3): Receptacles that are not readily accessible and are
supplied by a branch circuit dedicated to electric snow-melting, deicing,
or pipeline and vessel heating equipment shall be permitted to be installed
in accordance with 426.28 or 427.22, as applicable.
 

kwired

Electron manager
Leakage detector is basically same thing as GFPE and very possible that any minor leakage will trip GFCI but not the leakage detector simply because of lower trip threshold of the GFCI.

Any situation where there is enough fault current to trip both will mean you must reset both, but having both doesn't create any interference of any kind between them.
 

GeorgeB

ElectroHydraulics engineer (retired)
Can a GFI be fed by a GFI without causing any undesirable effects and nuisance tripping?
When I hooked my test equipment (3 120VAC devices) at a customers' pants, I used a GFCI triple outlet short cable. This is one of those that has to be reset every time power is lost (is unplugged). I never tripped the GFCI many plants had on the production floor.
 
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