SUBMERSIBLE PUMP WON'T START

[mconnell61]

Hello,

This is a great forum and I am hoping that the adept members can help me with the problem I am having with my well pump.

I have a submersible pump that I hooked up to a 20 amp, 2 pole breaker in my main panel. I did some research and learned that most 220v pumps require a 30 amp breaker with 10 gauge wire from the breaker to the pump.

However, after doing some more research I learned that some well pump professionals use a 20 amp, 2 pole breaker with 12 gauge wire as long as it is a dedicated line with only the well pump connected to it. So, I used a 20 amp, 2 pole breaker with 12 gauge wire from the breaker to the gang box where it connects to the pump wires which are 10 gauge wires. It is a 2 wire submersible pump (3 wires with the ground wire). The wires are red, black and green.

When I turn the breaker on I get 220v power all the way to the gang box where the pump wires hook up (tested it with a voltmeter), but when I turn the manual power switch on (that is upstream from the gang box) the pump will not turn.

I have been working on this situation for several days and I have some ideas about what the problem might be here:

It could be that the 12 gauge wires coming from the breaker to gang box are not sufficient to accommodate the amount of amps that are required to power the pump (which has 10 gauge wires for good reason I am thinking).

Or, it is possible that when I was hooking up the pump wires to the power wires in the gang box I accidentally pulled one, or all of the pump wires loose where they connect to the pump down in the well.

Finally, I am thinking that maybe the pump just died on me and needs to be replaced. This scenario seems unlikely though because the pump was working fine for about 4 years while hooked up to a 220v generator with a 10 gauge extension cord. I ran the pump the day before I started this project to hook it up to the 20 amp, 2 pole breaker in my main power panel and it was fine.

I would be extremely grateful if any forum members could respond and let me know if any of my theories are correct. If, not then any other solutions offered would be much appreciated.

Thank you in advance.

 

[Valveman]

You need a clip around ac amp meter. No amps, wire broke. High amps, wires crossed. Correct amps, pipe broken.

 

[MicEd69]

Valveman provided you the answers to determine what's wrong with your pump/wiring.

But in regard to the wiring and breaker, they need to be sized based on the current draw for the motor. The current draw for a motor is based on the power of the motor, i.e. the motor rated horsepower. The size of wire is determined by the amperage required NOT the voltage.

Your smaller 12-gauge wire is protected by your 20-amp breaker. If your 20-amp breaker tripped when you tried to start the pump, then your breaker and your 12-gauge wire is too small. From your description, your breaker did not trip when you tried to start your pump, so something is broken. But if your breaker did trip, then that is at least one of your problems.

 

[havasu]

One question that I believe would be paramount is ..... what is the length of the run?

 

[Valveman]

One question that I believe would be paramount is ..... what is the length of the run?

And horsepower of the motor?

 

[mconnell61]

You need a clip around ac amp meter. No amps, wire broke. High amps, wires crossed. Correct amps, pipe broken.

Thank you for the reply Valveman. I will buy a clip around ac amp meter and test it.

 

[mconnell61]

Valveman provided you the answers to determine what's wrong with your pump/wiring.

But in regard to the wiring and breaker, they need to be sized based on the current draw for the motor. The current draw for a motor is based on the power of the motor, i.e. the motor rated horsepower. The size of wire is determined by the amperage required NOT the voltage.

Your smaller 12-gauge wire is protected by your 20-amp breaker. If your 20-amp breaker tripped when you tried to start the pump, then your breaker and your 12-gauge wire is too small. From your description, your breaker did not trip when you tried to start your pump, so something is broken. But if your breaker did trip, then that is at least one of your problems.

Much appreciated information MicEd69.

I do not know the horsepower of the pump so I do not know how many amps it draws. I bought the property with the new submersible pump already installed in the well. I searched around the well head and all around the well house for a decal or plaque that might have information about the pump but I found nothing.

As to whether or not the breaker tripped, you are correct, it did not trip. So it sounds like the most likely scenario is that I accidentally disconnected one or more wires that connect to the pump down in the well just by pulling the wires slightly up into the gang box where I connected them to the 220v power wires. As I stated in the original post, I don't think the motor is broken because it was working fine the day before I started this project.

 

[mconnell61]

And horsepower of the motor?

The well is about 150 ft deep I was told by the previous owner when I bought the property. The distance between the breaker in the main panel and the gang box where it connects to the well pump wires is about 30 feet making the total run about 180 feet.

I don't know the horsepower of the pump because it was already in the well when the property was purchased.

 

[Valveman]

Wire size is not the problem. With 20 amp breakers it is probably a 1/2HP pump and #12 wire is good to 650'.

 

[mconnell61]

Wire size is not the problem. With 20 amp breakers it is probably a 1/2HP pump and #12 wire is good to 650'.

Okay. It looks like I am going to have to pull the pump out of the well and check the wire connections.

 

[Valveman]

Always amp and ohm test before pulling the pump. Be mad if you pull pump and find bad connection up top.

 

[mconnell61]

Always amp and ohm test before pulling the pump. Be mad if you pull pump and find bad connection up top.

If I have confirmation that 220v power is reaching the gang box where the well pump wires connect and the 12 gauge wire coming from the 20 amp breaker to the gang box is not a problem then what "bad connection up top" might there be for me to check?

 

[MicEd69]

So just to confirm:

1. You have NOT run the pump with the 12-gauge wiring or the 20-amp breaker.
2. You HAVE been running the pump with a 10-gauge extension cord on a 30-amp breaker.
3. The existing wiring from the gang box to the pump is 10 gauge.

If all that is true, then you MAY still have a problem with the wiring.

However, that problem is NOT the problem you are now experiencing because the pump won't start. IF the wiring and breaker are a problem, when you try to start the pump, the pump will draw more amps than the 20-amp breaker can supply. The breaker will then trip to protect the 12-gauge wire.

If/when you pull the pump, verify the pump horsepower.

Too bad you didn't have an amperage reading on your pump when it was working and before you downsized the wiring and breaker to confirm that reduction would positively work.

 

[mconnell61]

So just to confirm:

1. You have NOT run the pump with the 12-gauge wiring or the 20-amp breaker.
2. You HAVE been running the pump with a 10-gauge extension cord on a 30-amp breaker.
3. The existing wiring from the gang box to the pump is 10 gauge.

If all that is true, then you MAY still have a problem with the wiring.

However, that problem is NOT the problem you are now experiencing because the pump won't start. IF the wiring and breaker are a problem, when you try to start the pump, the pump will draw more amps than the 20-amp breaker can supply. The breaker will then trip to protect the 12-gauge wire.

If/when you pull the pump, verify the pump horsepower.

Too bad you didn't have an amperage reading on your pump when it was working and before you downsized the wiring and breaker to confirm that reduction would positively work.

Yes, I confirm that all three of those statements are true with one added detail in regards to the second one. I have been running the pump on a 10 gauge extension cord that was plugged into a 30 amp outlet of a generator, not municipal power (Edison). Not sure if there's any difference.

As for the 12 gauge wire size and 20 amp breaker I do confirm that the breaker did NOT trip when I tried to turn on the pump.

I was thinking about replacing the 20 amp breaker with a 30 amp breaker as well as putting 10 gauge instead of 12 gauge wire that runs from the breaker to the gang box where it connects to the 10 gauge pump wires. However, since the 20 amp breaker did not trip this probably would not fix the problem with the pump not starting.

The bottom line here is that I am getting 220v power to the gang box where it connects to the well pump wires and the breaker doesn't trip when I try to start the pump so it seems like my only option left is to pull the pump. It is probably either a wire that has come disconnected at the pump or the pump is bad. Either way, it seems like I will need to pull the pump unless someone can suggest something else I can try that has not been mentioned yet.

 

[mconnell61]

So just to confirm:

1. You have NOT run the pump with the 12-gauge wiring or the 20-amp breaker.
2. You HAVE been running the pump with a 10-gauge extension cord on a 30-amp breaker.
3. The existing wiring from the gang box to the pump is 10 gauge.

If all that is true, then you MAY still have a problem with the wiring.

However, that problem is NOT the problem you are now experiencing because the pump won't start. IF the wiring and breaker are a problem, when you try to start the pump, the pump will draw more amps than the 20-amp breaker can supply. The breaker will then trip to protect the 12-gauge wire.

If/when you pull the pump, verify the pump horsepower.

Too bad you didn't have an amperage reading on your pump when it was working and before you downsized the wiring and breaker to confirm that reduction would positively work.

I actually never downsized the wiring and breaker. This is the first time I have connected this pump to my main breaker box. Before this I was only running the pump with a 220v generator.

 

[MicEd69]

As I said and as you noted, since you have power to the gang box that connects the wiring from your power source to the pump wiring, the size of the wire and the breaker size is NOT the problem of why your pump won't start. I do assume when you say that you have power to the gang box that that means you have power to the wiring that is going to your pump, not just power to your control system.

And it makes no difference as to the power source, generator or power company, on the breaker or the wiring sizes.

When I said "you downsized the wiring and breaker", I meant you had been running the pump through a 30-amp breaker and with 10-gauge wire. Now you are planning to run it through a 20-amp breaker and 12-gauge wire. That will absolutely work just fine IF the power requirements of the pump are not higher than 20 amps. As the pump wiring to the pump from the gang box is 10 gauge, if/when you pull the pump you may find that your pump requires more than 20 amps. If that is what you find, and you try to run it through a 20-amp breaker and 12-gauge wire, you will likely be tripping the breaker routinely. Again, the breaker's purpose is to protect the wiring.

 

[Twowaxhack]

Hook the generator back up and see if it’ll run the pump like before you messed with it.

 

[mconnell61]

As I said and as you noted, since you have power to the gang box that connects the wiring from your power source to the pump wiring, the size of the wire and the breaker size is NOT the problem of why your pump won't start. I do assume when you say that you have power to the gang box that that means you have power to the wiring that is going to your pump, not just power to your control system.

And it makes no difference as to the power source, generator or power company, on the breaker or the wiring sizes.

When I said "you downsized the wiring and breaker", I meant you had been running the pump through a 30-amp breaker and with 10-gauge wire. Now you are planning to run it through a 20-amp breaker and 12-gauge wire. That will absolutely work just fine IF the power requirements of the pump are not higher than 20 amps. As the pump wiring to the pump from the gang box is 10 gauge, if/when you pull the pump you may find that your pump requires more than 20 amps. If that is what you find, and you try to run it through a 20-amp breaker and 12-gauge wire, you will likely be tripping the breaker routinely. Again, the breaker's purpose is to protect the wiring.

So if the breaker

Hook the generator back up and see if it’ll run the pump like before you messed with it.

Thanks for the suggestion. Unfortunately, the generator is broke. That is why I am trying to power the pump with municipal power now.

 

[mconnell61]

As I said and as you noted, since you have power to the gang box that connects the wiring from your power source to the pump wiring, the size of the wire and the breaker size is NOT the problem of why your pump won't start. I do assume when you say that you have power to the gang box that that means you have power to the wiring that is going to your pump, not just power to your control system.

And it makes no difference as to the power source, generator or power company, on the breaker or the wiring sizes.

When I said "you downsized the wiring and breaker", I meant you had been running the pump through a 30-amp breaker and with 10-gauge wire. Now you are planning to run it through a 20-amp breaker and 12-gauge wire. That will absolutely work just fine IF the power requirements of the pump are not higher than 20 amps. As the pump wiring to the pump from the gang box is 10 gauge, if/when you pull the pump you may find that your pump requires more than 20 amps. If that is what you find, and you try to run it through a 20-amp breaker and 12-gauge wire, you will likely be tripping the breaker routinely. Again, the breaker's purpose is to protect the wiring.

So if the 20 amp breaker isn't tripping off when I try to turn the pump on doesn't that confirm that my pump is not requiring more than 20 amps?

 

[mconnell61]

So if the 20 amp breaker isn't tripping off when I try to turn the pump on doesn't that confirm that my pump is not requiring more than 20 amps?

Yes, I do have 220v power connected to the pump wires in the gang box.