240volt well pump with 1 phase drawing 11 amps

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joe205

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i had a call for a well pump not working. 240volt 1/2hp or 3/4hp not sure. pump is about 275' down with two #12- no ground. volt meter indicates 242volts at top of casing. 11.0 amps on phase b zero amps on phase a. with power on pressure gage shows around 10lbs.
what could be probable cause?
 
joe205 said:
i had a call for a well pump not working. 240volt 1/2hp or 3/4hp not sure. pump is about 275' down with two #12- no ground. volt meter indicates 242volts at top of casing. 11.0 amps on phase b zero amps on phase a. with power on pressure gauge shows around 10lbs.
what could be probable cause?
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Most well cables I've seen have three or four wires, one of which is green. Mine were all capacitor start. Is it a pre-fab cable or a homemade pair of wires? #12 seems kinda small for a well that deep. A megger would determine a ground fault. There should not be any circuit to ground on any well pump I know of. Megger it disconnected to eliminate any damage or misreadings due to control components. Could be the wires going to the pump instead of the motor. They're pretty long and can be damaged by improper installation. Any continuity across the winding? If so, both legs will show a ground fault. You said it doesn't work, but shows 10 lbs when powered. Is it running? If so, it could be a control problem. Are you using an amp clamp? Most likely it's pull the pump time, though. Big bucks...ask me how I know!:cry:
 
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meternerd said:
Most well cables I've seen have three or four wires, one of which is green. Mine were all capacitor start. Is it a pre-fab cable or a homemade pair of wires? #12 seems kinda small for a well that deep. A megger would determine a ground fault. There should not be any circuit to ground on any well pump I know of. Megger it disconnected to eliminate any damage or misreadings due to control components. Could be the wires going to the pump instead of the motor. They're pretty long and can be damaged by improper installation. Any continuity across the winding? If so, both legs will show a ground fault. You said it doesn't work, but shows 10 lbs when powered. Is it running? If so, it could be a control problem. Are you using an amp clamp? Most likely it's pull the pump time, though. Big bucks...ask me how I know!:cry:
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It seemed to be a common practice at one time to not run an EGC down the well casing to the pump motor, there are older submersible cables that didn't have a green conductor.
 
kwired said:
It seemed to be a common practice at one time to not run an EGC down the well casing to the pump motor, there are older submersible cables that didn't have a green conductor.
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It was hard to break some of the installers of that habit and then to add a bond to the well casing. Forget it. I had one in the area that refused to do it at first.

That has changed dramatically since all new wells now require an inspection. Not necessarily an Electrical inspection.
 
ptonsparky said:
It was hard to break some of the installers of that habit and then to add a bond to the well casing. Forget it. I had one in the area that refused to do it at first.

That has changed dramatically since all new wells now require an inspection. Not necessarily an Electrical inspection.
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Something in your local area? Not aware of any well inspections up this way. NRD may do some inspections I believe, and may be somewhat random or ay depend on pumped volume, but they are not concerned with electrical at all, but rather ground water quality protection.
 
kwired said:
Something in your local area? Not aware of any well inspections up this way. NRD may do some inspections I believe, and may be somewhat random or ay depend on pumped volume, but they are not concerned with electrical at all, but rather ground water quality protection.
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It is statewide and does have more to do with the construction of the well but they do look at the electrical while there. All new wells are supposed to be registered with the State.
 
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Every single phase well I have worked on has a start array with capacitors and potential relay etc. Some also have manual RST overloads.
All I have worked on had grounds to the submersible which are supposed to be connected when its dropped in. There is usually a splice that your rated cable is mde up to and heat shrinked over.
Just like HVACR loads that section is prone to failure and has to be checked out with any service to be sure its intact.
Failed start components can ruin a new motor quickly.
 
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