GFI

[Mickpat]

I have an issue that is puzzling me.

I have an outdoor fountain that has two submersible pumps.  I have been using 1 pump for about 2 years and another has never been run, but has been underwater all this time.  Last week I reconnected the second pump and water flooded the area near the fountain and the GFI triggered.  Now, connecting either pump causes the GFI to trigger.
I can’t figure out why.  Here is what I have tried.

• From the outdoor outlet I installed, plugging in either pump causes the GFI to trip after the pump runs for 5 – 10 seconds.
• I connected an extension cord to a different GFI outlet to pump A then pump B.  Both pumps trigger the second GFI.  This rules out an issues with the outdoor outlet I installed.  (Kind of disappointing because this would be an easier problem to solve.)
  
• So, I believe that BOTH pumps have failed or both cords to the pumps are damaged.  Maybe flooding the area exposed the problem, but it rains all of time here in Seattle so I can’t believe this would just start happening now.

Any ideas?   The cords are under soil and rock making it impossible to inspect the entire cord. 

[shaunkad]

Take a multi meter and ohm the 3 pins on the plugs. Odds are they are shorted or open causing the problem you should get some resistance between the hot and the neutral and open to ground. if this does not help the next step would be to find someone with a megohm meter that knows how to use it.       

[tng5737]

make sure that all your connections are dry - perhaps the flooding caused water to to get into a connector which would cause the GIF's to trip

[chrisatpsu]

I've noticed with can lights, if yourground and neutral shorts, it trips a gfci

[caretaker]

First I will take it the GFI didn't get wet when the area flooded, if so replace the GFI with a new one that is marked WR they are the newest code required GFI's required for outside areas and will stand up to the weather better. Now if the GFI didn't get wet you are getting a ground fault issue which to solve may require you to remove both the pumps to allow them to dry out and see if there is any cord damage/ water seepage. If it were me, I would replace the GFI anyway as once they trip a few times they can become "weak" and nuisance trip.

[rm357]

My guess would be that you got some dirty water in a connector somewhere that is creating a conduction path... I'd pull everything out and give it a good inspection. If there are any places where water might have leaked, I'd see if I can safetly take it apart, wash stuff with clean water, let it dry, then reassemble/reseal...

The GFI trips when the current on the hot lead and neutral are not the same - that means that some current is finding an alternate path to ground...

RM