I live in the country and I get my water from a well. I have a mysterious gurgling noise coming from the interior of the electric cable housing which supplies electricity to the pump at my well head. The pump is approx. 300 feet deep and when I remove the cover of the pump control box I can hear a gurgling noise which sounds almost like boiling water. However, there is no smoke, steam or smell of either coming from the cable housing. The pump operates normal in all respects. When I turn the power to the pump off it continues to gurgle or boil. No noticeable change in the sound after 15 minutes.
Any help will be appreciated.
Chuck

Sounds like a high resistance short is occurring in the cable to create the noise you hear. A high resistance short can exist in the cable, current will flow at what would seem to be lower than the breaker rating, so the breaker thinks it is a normal load.

One way to determine if there is a short is to measure the amps in the circuit when the motor is not running. If you see any current flow, then the cable and/or pump needs to be replaced.

There are other tests that can be done, such as meggering, but the motor needs to be disconnected, and this of course means it needs to be pulled out of the well.

With this noise you hear, I am sure you will need to pull the cable and pump out to find the problem and repair as necessary. The test I offer is only to confirm a problem.

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Originally Posted by tkrussell

Sounds like a high resistance short is occurring in the cable to create the noise you hear. A high resistance short can exist in the cable, current will flow at what would seem to be lower than the breaker rating, so the breaker thinks it is a normal load.

One way to determine if there is a short is to measure the amps in the circuit when the motor is not running. If you see any current flow, then the cable and/or pump needs to be replaced.

There are other tests that can be done, such as meggering, but the motor needs to be disconnected, and this of course means it needs to be pulled out of the well.

With this noise you hear, I am sure you wil need to pull the cable and pump out to find the problem and repair as necessary. The test I offer is only to confirm a problem.

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This morning the sound is gone! In your opinion, what is the urgency for pulling the pump?

Depends on how long you did hear the noise. If there is any event going on down in the cable, it will only get worse. And always fail when you least need it.

The fault I described that will cause the bubbling noise is a high resistance short, current is flowing between both hot legs or one hot leg to ground, but the material is such that there is most likely carbon from the heat of a break in a wire. This heat will continue to a certain point that will ultimately melt the copper and the circuit will be open, and the pump will not run.

This is a popular problem found in underground wiring for parking lot lights, and the such. We can hear the water in the conduits boiling, and with conduit you can see the steam.

We electricians are only on scene after the damage has been done, so I unfortunately cannot speculate as to when this started and how far along this is.

You can wait it out and take your chances, just be ready to repair it when it does fail.