Hi all...I just bought a house with an in-ground pool, and I'm having some issues with the wiring. One specific issue concerns an outdoor outlet supplying power to the pool pump. When we moved in about 2 weeks ago, the pool hadn't been run for a while and we had the pump going pretty much 24/7 for a week to clear out the algae. It cleared out fine and we'd cut back on running the pump. The other morning my wife went out and plugged in the pump and it must have tripped the breaker and she kept re-setting the GFCI breaker (not really understanding the idea) and this appears to have fried the outlet...see photo. It is so melted that I could barely get a set of probes in there, which read the current as around 36V, but since the outer plastic has moved I can't really get a good contact. The plug for the pump has some definite heat pitting on the blades also...I'm attaching a photo of that as well. Obviously the outlet has to be replaced (I'm re-doing the entire pool area anyhow) but I'd like to figure out why it melted and the first place and correct it before I proceed any further. The power supply for the outlet seems to come out of the dirt with no sign of any conduit. although I have not yet dug down to ascertain this. Any thoughts as to what I should do first, or why the breaker was so overloaded as to keep tripping? I'm definitely testing the underground wire ASAP.
Many thanks in advance...

 

The reason why it melted was likely a poor connection due to corrosion, or old/worn device. Bad connection create heat which is why it melted.

First thing you should do is replace the receptacle with a new device, and replace the cord cap in the picture. You might want to even go with a twist lock plug and receptacle to insure good contact. This won't work if you use this receptacle for other things other then the pump throughout the year.

Then check to make sure you have proper voltage/ground.

Next install an in use cover, which is required by code now. This will help keep everything dry when the cord is plugged in.

 

The burnt blades on the plug tell me the receptacle was old and worn and probably the source of your problem. I have never seen a pump for an inground pool that was controlled by plugging it in; a poor setup in my opinion. I'd suggest hardwiring and controlling the pump with a switch.