GFI problem needs something plugged in to work??

[PaulMac]

Hi all,

I have a weird situation with my GFI circuit connected to 3 garage outlets, 2 ceiling lights, 2 garage doors openers, and one outside outlet. It seems that in order for the circuit to work, ie to provide power to the entire GFI circuit, I have to have something plugged in to one of the first outlets inside the garage. I plugged in a little night light that draws low current and all of sudden the entire system kicks on and starts work.

I have inspected the connections, tightened them all in the receptacles, etc and nothing seems burnt or frayed, but just this weird fluke. I am not an electrician but fairly handy with the DIY electrical stuff (volt meters, etc) but can't figure out why having something plugged in would cause the system to work?

Is there a short that is overriden by a light load on the circuit? Is there water in the outside plug causing intermittant power? Any thoughts would be welcome.

P

 

[hj]

I would guess you have an open neutral wire, and plugging something in establishes a neutral through it.

 

[Sponsor]

 

[PaulMac]

I would guess you have an open neutral wire, and plugging something in establishes a neutral through it.

Hi Hj,

 

[PaulMac]

I would guess you have an open neutral wire, and plugging something in establishes a neutral through it.

Good advice and diagnosis. I found a loose connection on the neutral wire and ended up replacing the outlet. Everything works fine now.

 

[Jadnashua]

A GFCI works by measuring the power going out the hot lead and returning on the neutral. If they're different by more than 5ma, it will trip and not let you reset. It does not need ground to work. But, because ground and neutral are tied together back in the panel, except for potential resistance because of the wire length, gauge, and any connections, a 3-pin plug may tie the neutral and ground together inside of the device it powers, and create a substitute path, allowing it to 'think' all is well. Ground is not supposed to be used as a normal current path, so could create problems because it could overload that wire. FWIW, the ground wire is allowed to be smaller than the normal power conductors, and could be overloaded and then heat up without tripping anything until it melted something and shorted out.

 

[PaulMac]

Thanks for the additional info Jadnashua very helpful for the novice like me. I managed to fix it.