submersible well pump, thermal overload question


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Old 02-26-11, 12:00 AM
C
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submersible well pump, thermal overload question

Hi folks:

I had a contractor come out to my cabin to install someone linoleum in my utility room that required removing a hot water tank, pressure tank, and then a washer and dryer. This was a final stage in some flood damage. The plumber neglected to depressurize the system or turn off the breaker to the well pump. Don't get me started on how incompetent I think the guy was--a general contractor hired him.

Needless to say this started a flood when he tried to dismantle the pipes, and in a panic to shut the water off, the main valve from the well was shut off, (before pressure switch) but the power was left on to the pump. I have no idea how long the pump ran, but it could have been as much as 8 hours.

The unfortunate news is that a threaded fitting from the pit-less broke underground causing hundreds of gallons of water to pool by the well head. Since this was part of an insurance claim, it now becomes a case of proving negligence.

The total repair cost was over $4700 as the ground had to be dug up at -35 below temperatures.

So, the question I have is concerning thermal overload protection of the of the well pump. How long could a pump run before it would overheat and shut off? Could it build up enough pressure in this time to rupture a pipe? The only specs I know on the pump is it is a Taylor brand, (from Home Depot) and is about 80 feet down in a 180 foot deep well. The well head is 114 feet from the house. GPM run 11.25. Don't know HP, but it is a 220 model with controller box.

The water was working fine prior to the contractor showing up, and did not work when he left. The contractor is claiming something else caused the break, but cause-and-effect tells me different.

So, can someone give me some scenarios here as to what happened? I'm thinking excess pressure built up and broke the pipe. The pipe has never frozen underground; in fact, the pitless is nearly 9 feet underground. The frost level was only at about 2 feet when it was dug up recently.

The well driller who dug up the ground claimed that the fittings are rated to 450lbs of pressure. Considering the incredible water pressure I have in the cabin, I would think that the pump would be capable of generating this much pressure, but I don't know. It is possible that the underground fitting was stressed too by poor backfilling, etc. Everything is 3/4" copper underground, and I believe they used compression fittings. The threads on a male adapter is where it broke.

Comments?
 
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Old 02-26-11, 05:23 PM
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hi cwphoto –

Sorry I can’t be of much help. I’m a newbie and know little. But I don’t think your submersible pump would overheat as long as it had water to pump. I believe they can run indefinitely and won’t overheat as long as the well doesn’t run dry, or I guess if the well recovers soon enough. I think it’s the start and stops that are rough on the pump – not continuous running. My understanding is that the water keeps them cool enough as they run and so they can just keep on going and going without a problem. But the pro’s would have to verify that.

Wonder if that is a good configuration to have a shutoff before the pressure switch? Sounds dangerous in that the kind of accident you describe could easily happen. My shutoff is after the pressure switch. But like I said, I’m a newbie and could be all wet.

Hope the pro’s jump in.

Good luck!
 
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Old 02-27-11, 07:42 PM
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That is a terrible story, I hope things get better for you.
I would be more incline to believe that maybe ground shift may have caused the brake.
A submersible pump will not build anywhere near 450psi. Most stop pumping at around 120 to 150psi.
 
 

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