I usually understand how to do this but I am truly stumped.
There was a single GFI protected already in place and I wanted to run a switched 2 gang outlet from the box on my deck.
After turning power off, I installed an outdoor GFCI receptacle to an outdoor switch in a duplex receptacle as follows....

I connected the black and white wires from the house to the line side of the GFI, and corrected connected all of the ground wires together and to the box.

I then took a black, hot, wire from the load side of the GFI and put one leg of the switch on it.

I ran the white from the load side and the black from the other terminal of the switch to the outdoor wire that is buried and ends up about 40 feet away. I stalled a outdoor box with a waterproof receptacle to it and plugged in the pond pump.

I repowered the circuit check the circuit with a tester and got an O K reading. Turned the switch to on andthe pump ran for a while but then the circuit popped. Now it pops as soon as I switch on.
Should I have run the switch from the line side??

Can you please help?

  • What wiring method did you use for the buried run? Commented Apr 14, 2020 at 1:01
  • Just dug in gray 2wire with ground to downstream outlet mounted to weatherproof box on post
    – Michael D
    Commented Apr 14, 2020 at 3:02
  • You mean /2 UF cable when you say "gray 2 wire with ground" right? Commented Apr 14, 2020 at 4:33
  • Yes.... Also. When I reset the GFI on the deck it gives me a green light. When I plug even the tester in downstream, the circuit breaks.
    – Michael D
    Commented Apr 14, 2020 at 13:10

1 Answer 1


Check for a neutral-to-ground short somewhere downstream

The behavior you're describing (a GFCI resetting fine, but tripping instantly when any load is applied) is symptomatic of a neutral-to-ground fault in the wiring on the LOAD terminals. I'd unhook and nut off the wires currently attached to LOAD, and then see if the GFCI resets and powers a load at this point.

If it does, then you'll probably need to replace your buried cable run; note that it's no good to use UF for a pond pump branch circuit, as its ground wire is bare, which violates NEC 682.31(A):

(A) Type. Equipment grounding conductors shall be insulated copper conductors sized in accordance with 250.122 but not smaller than 12 AWG.

As a result, I'd redo this run using PVC conduit with individual THHN/THWN insulated wires (black, white, green) inside it; this fixes the Code issue with your existing install, in any case, for that matter.

  • Thank you! Tracked it to the final run of UF wire. I dug up the underground run of wire and found that I stupidly nicked it a few times with the large screwdriver I was using to push it into the hole I split with the spade. I was trying to make it easy! As a result, I dug the entire run and then just laid in new wire. It now works perfectly! Thank you
    – Michael D
    Commented Apr 18, 2020 at 15:16
  • @MichaelD -- did you replace the UF like for like, or did you replace it with THHN in PVC conduit? Also, we thank people around here by accepting and/or upvoting their answers :) Commented Apr 18, 2020 at 18:25

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