GFCI Temp Power

Status
Not open for further replies.
DBoone

DBoone

Senior Member
Location
Mississippi
Occupation
General Contractor
Was finishing a framing job Monday, after a rain, and the GFCI receptacles on the temp power pole kept tripping. Finally they got to where they wouldn't hold at all. Finally had to rush to get a generator so I could finish.

What do you do when you are on a job and the GFCIs keep tripping?

Can't get any work done.
 
jumper said:
Find the cause of the tripping.

After the rain, correct?

Unless the GFCIs have faulted themselves, equipment has a problem.

Is equipment holding on GFCI protection now?
Click to expand...


Yep right after a hard long rain. GFCIs would reset and hold for awhile and then trip. Later in the morning they would not hold at all when my extension cord was plugged in. They would hold when I unplugged my cord.

As far as I've seen my cords are in good shape. I had multiple cords hooked together.
 
DBoone said:
Yep right after a hard long rain. GFCIs would reset and hold for awhile and then trip. Later in the morning they would not hold at all when my extension cord was plugged in. They would hold when I unplugged my cord.

As far as I've seen my cords are in good shape. I had multiple cords hooked together.
Click to expand...

Under the right wet conditions I suppose enough current leakage at the connections could cause the problem.....maybe.

Whether this happened or something similar, I tend towards water and equipment causing a problem more than faulty GFCIs, unless they have already been banged up in the construction, which is quite often and normal.
 
jumper said:
Under the right wet conditions I suppose enough current leakage at the connections could cause the problem.....maybe.

Whether this happened or something similar, I tend towards water and equipment causing a problem more than faulty GFCIs, unless they have already been banged up in the construction, which is quite often and normal.
Click to expand...

I tend to lean towards this situation being leakage at the connections. And if I didn't have access to a generator I would have been in a predicament.
 
If the extension cords/ends are in good condition but damp/moist, and there is any salinity/alkalinity in the moisture to lower resistance, you can get trips. Get a can of Wire Dryer and spray off the ends.

If your cord/eqpt trips from multiple GFCI Receptacles, it's the cord or eqpt that's the problem. If it's just one, the receptacle may be going bad. Think about it, those receptacles frequently get wet/dirty plugs inserted and eventually you'll push gunk/dirt up inside of them.
 
Don't forget that as a practical matter there will be capacitance between the wires in a portable cord (which might be worse with water infiltration into the sheath). A long enough cord in perfect condition can trip a GFCI just based on the capacitance. (Usually not a practical problem, but can make the difference when other leakage less than the GFCI threshold is also present.

The thinner the insulation and the larger the cross section of the wire for the same insulation thickness the greater the capacitance per foot.
A balanced voltage 240V cord connected to a two pole GFCI will not exhibit this problem nearly as badly.
So use a long 120/240 cord connected as an MWBC to power spider boxes closer to the loads.
 
Status
Not open for further replies.
Top