# Well Pump Wiring



## BigGreen22 (Mar 12, 2008)

I am trying to wire up my well pump which is about 400 feet from the house. I believe it has a 1.5 hp motor. My questions are to find out what size wire I have to run and what size breaker it should have in the panel. Also, I'd like to know the different if the motor were to be 2 hp or 3 hp. Thanks for any help that can be provided.


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## Speedy Petey (Feb 1, 2004)

What did the well installer say? Usually they run the wire to the house.


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## BigGreen22 (Mar 12, 2008)

Unfortunately I purchased this house from the bank because it was being built but the builder couldn't finish it. I don't have much of a record to find out the information on so now I'm stuck trying to pick up the pieces. The well was in and the conduit had been run but the wire hasn't be ran through the conduit. I might have to call around and find out who put it in but I was hoping it would be easy to answer.


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## Speedy Petey (Feb 1, 2004)

Is there wire at the top of the well head? If so can you tell what size it is?


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## BigGreen22 (Mar 12, 2008)

Keep it simple right :thumbup: That's the easiest and best idea I've heard. I'll check it tonight and see what it is. How do I determine the breaker size to use?


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## mr500 (Mar 8, 2008)

On my well pump, I have it submersed in the well about 40 ft or so. In MY case, I ran 12-2 w/ gnd UF up and into a 20amp double pole breaker just below my meter. Mine is a 2 wire pump so wasn't that hard to connect. 

Like i said mine is submersed and I done what the guy at the parts house told me to do. Everything works out fine in my case. Yours may be different since your running a longer footage than mine. But im sure some of the others will chime on on this one. 

Mike:whistling2:


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## Speedy Petey (Feb 1, 2004)

If you are 400' out, and who knows how deep, it will likely be #8 or #6 wire.
You size the breaker according to the load. You need to know the exact load the motor pulls. At 1.5hp you will likely use a 20A breaker, two-pole of course.


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## USP45 (Dec 14, 2007)

Speedy Petey said:


> If you are 400' out, and who knows how deep, it will likely be #8 or #6 wire.
> You size the breaker according to the load. You need to know the exact load the motor pulls. At 1.5hp you will likely use a 20A breaker, two-pole of course.


i am a licensed master plumber and I must say that I agree, agree with one minor thing, WHAT VOLTAGE IS THE PUMP?
Most I install are 220, but the one at my house is a 110. Yes they do make a 110 volt submersable pump AND the new jet pumps are changable from 110 to 220. FIND THE VOLTAGE before you burn the pump.


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## BigGreen22 (Mar 12, 2008)

Any ideas on the best way to find out what the voltage is as well as to confirm the size and all? It's in the ground which is the trouble I've been running into.


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## mr500 (Mar 8, 2008)

GREEN,

Don't know if this helps, but my pump came with decals to affix to the inside of my breaker panel. Shows amps, volts, HP the whole 9 yard. don't know if thats the same in your case and u may have already looked there. Just to drop that in the mix

Mike


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## Speedy Petey (Feb 1, 2004)

USP is correct, but I have never seen a 120v deep well pump. By deep well I mean ~75' and down. 
This is especially true for larger pumps such as the OP's 1.5hp. 
Consider the voltage drop on a 120v 1.5hp motor at +/-600' !! It would be near impossible to circuit a motor like that as 120v.
This is why they are typically 240v.

Jet pumps are typically 120v, but as stated usually can be converted to 240v.


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## USP45 (Dec 14, 2007)

Speedy Petey said:


> USP is correct, but I have never seen a 120v deep well pump. By deep well I mean ~75' and down.
> This is especially true for larger pumps such as the OP's 1.5hp.
> Consider the voltage drop on a 120v 1.5hp motor at +/-600' !! It would be near impossible to circuit a motor like that as 120v.
> This is why they are typically 240v.
> ...


Speedy, yes they do make deep well pumps 120 volt. When I bought my house they made the real estate pay for a new well. They did not want to spend much money (Typical huh?) so they used a 120 volt pump. This thing has been pumping now for 27 years and is still going strong.


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## Speedy Petey (Feb 1, 2004)

Oh, I know they are made. And in situations like yours they get installed. Obviously your installation is not so bad that it has lasted many years.

Like I said though, at very long distances/depths you would need HUGE wire because the voltage drop would be prohibitive.

240v is MUCH easier on the equipment.


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## billie_t (Feb 17, 2008)

if the pump is in the well...there must be a junction box where the pump wires are "waiting" for you to hook them up....what size and how many are their....and you mus find out if your pump needs a starter above the well or if it is built in to the pump...if you can't find the company who put the pump in the well ..you may be forced to pull it and get the info from the pump itself..

most new installations are 220 volt single phase in new homes...but some have the starter built in and some don't...good luck


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## micromind (Mar 9, 2008)

Single phase submersible pump motors come in two types. 2 wire, and 3 wire. They are almost always 230 volt, some of the smaller ones (1/2HP and less) are 115. 

The 2 wire type needs only 2 wires + a ground to operate. It doesn't need a control box. The pressure switch starts and stops it directly. Overloads are usually built into the motor. 

The 3 wire type needs a control box. The start switch, start (and sometimes run) capacitors , overloads, and magnetic contactor (on larger motors) are in this box. It needs 3 wires + a ground from this box to the motor. On smaller motors, 2 wires feed the box, through the pressure switch. On larger ones, 2 wires feed the box directly, and the pressure switch goes to the box as well. 

Look inside the well casing. If there's 2 wires and a ground, you have a 2 wire motor. If it's 3, check for continuity between all 3 wires, occasionally the installer will only have 3 wire cable and will use just 2 for a 2 wire motor. 

A 1 1/2HP single phase motor on 230 volts will draw about 10 amps. Starting current will be about 60. At 400 feet, I'd run #8's if the well is less than 50' deep. If more than 50', I'd run #6's. If you're using AL, go up two sizes. A 20 amp breaker will run a 1 1/2 motor just fine. I'd run #12's from the panel to the control box or pressure switch, if it's not very long. 

Basically, if it's 2HP, increase the above by one size. For 3HP, go up another size. 

Is there a pull string in the conduit? If not, let us know, alot of us have different ways to pull something that long. 

Rob.


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## BigGreen22 (Mar 12, 2008)

Just as a follow up on the well I got it wired. I was able to track down the company that installed it. I've got a 1.5 hp well pump with 3/4 hp pressure pump. So for that amount I rounded to 3 hp total. #4 copper gets me out to 1190 feet so I ran that. It's 230 so two wires down (which ended up being 510 feet one way) and then ran a ground rod at the well and ran #4 to it. It's all installed on 40 amp 2 pole breaker and so far so good. I appreciate all the input. 

BTW, as for the conduit it did not have the pull cord run so I used my compressor and pushed the line through with a foam cylinder (not sure what they're called). Worked like a charm and ran the whole way with ease. Next I get to try the same thing on 4 inch conduit for 1200 feet. I may have to hook up all 3 compressors to get enough air to push it thru.


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## Speedy Petey (Feb 1, 2004)

WHY did you sink a ground rod at the well?????


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## BigGreen22 (Mar 12, 2008)

It was cheaper than running another #4 copper wire the 515 feet so instead I ran a new ground at the well. That's what the well company told me to do to save a lot of money.


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## Stubbie (Jan 7, 2007)

Speedy... is he saying he didn't run a equipment ground with the well branch circuit?


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## BigGreen22 (Mar 12, 2008)

That's what I'm saying but I'm starting to feel like the newbie that screwed up. I was told that this would be fine but perhaps my source is wrong. Is it required to run a ground from the box or is it possible to run only the two down and run a ground rod at the well and ground to this?


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## chris75 (Aug 25, 2007)

BigGreen22 said:


> It was cheaper than running another #4 copper wire the 515 feet so instead I ran a new ground at the well. That's what the well company told me to do to save a lot of money.


Yikes!, looks like your going to need an equipment ground...


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## Stubbie (Jan 7, 2007)

Big Green

Your source was ...dead...wrong 

Hmmmm....this is not the first time the purpose of the ground rod and equipment ground got screwed up. 

That ground rod is for huge voltage events like lightning to protect property and actually wasn't required to be even installed in your application. However the well head makes for a great grounding electrode....when its closer to the house....

The equipment ground provides for the opening of the well motor branch circuit overcurrent device (circuit breaker) back at the panel to save your behind in the event of a ground fault or short circuit.

A ground rod has too much impedance/resistance to allow enough current to flow through the breaker to open it in the event of fault at the well or anywhere on the branch circuit. What you ave right now is the possibility of all the metal at the well to become energized at line voltage and the breaker will not open. You come along or someone else and if a fault exists you get your !!!!!!! knocked in the dirt or worse.


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## Speedy Petey (Feb 1, 2004)

I glanced right over the "two wire 230v".

Yes, that is most certainly WRONG as the others have pointed out!

I STRONGLY suggest you tell your "source" that _several_ qualified electricians told you this is very wrong and that they should STOP giving out such erroneous and DANGEROUS advice.


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## BigGreen22 (Mar 12, 2008)

I'm sure glad that I haven't been using it much. It's connected to a generator so doesn't run much currently and won't be any more until setup correctly. So let me get it right this time and once again get some brainstorming done on how to get the next wire through. Now that two are in how do I run more? I'm not sure how I will get another pull cord down the 500 feet of conduit. As for the other wire, since my main wires are #4 does the ground have to be #4? Also, do I need only the two hot wire's down and the ground or does there need to be 4 down (2 hot, neutral and ground)?
Thanks again for catching my mistake. I'm thankful I posted what I did.


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## Stubbie (Jan 7, 2007)

Disconnect both wires at each end tie a a pull string to the wires at the circuit breaker end pull both wires out at the opposite end. This will pull in the pull string. then tie on all three wires and repull them. Hopefully you have big enough conduit because you need a #4 ground as well. You can go either way but my thinking is at the 'well' it will be easier to manage the cable as you pull it out.

In your case you have a 1 1/2h/p motor and a 3/4 h/p motor at the well. 10 amps x 1.25 + 7 amps = 19.5 amps. So a 20 amp branch circuit would have ran these motors before voltage drop. There is no size reduction for a 20 amp branch circuit in table 250.122 for the ground wire.. so the increase in equipment ground wire size would be 1:1 so the branch circuit also requires a #4 ground. This is all a result of the distance involved and you must be able to have low enough voltage drop on fault to allow enough current to return to the source (center tap of utility transformer) to open the breaker.


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## BigGreen22 (Mar 12, 2008)

What size breaker is needed in this application? I have a 40 amp in but not sure if that is too big based upon your comments. Pulling the wire through will be so much fun. Thanks for the help. I figured this was what is necessary but just needed someone to say it. It's 2 inch conduit so should be big enough. 
BTW, since I've got the ground rod in at the well and it's attached should I leave it hooked up or does it matter? Just wondering if it would do any good or if it's doesn't matter at all.


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## Stubbie (Jan 7, 2007)

Actually in your application operating two motors on the same branch circuit requires a feeder calculation in the event both motors start at the same time.

10 x 2.5 = 25 amps + 7 amps = 32 amps next size down is 30 AMPS.

So your maximum breaker should be 30 amps.

Leave the ground rod it won't hurt a thing.


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