Voltage choice for jet(?) pump

[mappley811]

Hi guys,
I recently bought a house with a well. Coming from a house on public water, the intricacies of well equipment are a new topic for me. I'm looking to buy a standby generator for my house during power outages, and I wanted to find out if my pump was 115 or 230 volt.

First of all, the placard on the external (jet?) pump (photo 1) says that it can run on 115v or 230v. Fine, no problem. There's also a sticker on the pump housing (photo 2) that says it's wired for 230v. All good still. Here's where the questions begin.

First, I noticed that there are only 2 conductors coming into the wiring box; black and white, and two leaving the box into the pump (blue-black) (photo 2). To me, a hot and a neutral says 115v. So I checked the panel, and there is only a single pole, 20A breaker marked out for the pump (photo 3), which also tells me 115v.

So my questions are the following:

1. Is this definitely wired for 115v?
2. What are the advantages/disadvantages of the 115v vs. 230v option?
3. Should I be looking into rewiring this to 230v before I buy a generator? It will mean buying a 240v generator instead of a 120v, so I'd like to know now.
4. If I did rewire it to 230v, where would the third conductor go? I don't see an additional terminal available, and I can't make sense of the directions on the wiring diagram in photo 1.

Thanks in advance for any help!

 

[Valveman]

The third wire is just a ground. It should be tied to the green screw in the pressure switch case. You probably have a double breaker, which means it is 240V. There is just no ground wire attached for safety. See where the voltage selection is set inside the motor.

240V is half the amperage of 115V. So 240V runs cooler, can use smaller wire, and has half the amperage for the pressure switch points.

Looks like you have a bare wire tied to the ground in the pressure switch.

 

[Sponsor]

 

[mappley811]

Other than being 20A, the breaker for the well pump is the exact same breaker as every other one in the panel (you can see it in the third picture, it's in the #8 slot). I don't see how it could be providing 240V on a single pole. Is that even possible?

 

[Reach4]

Get a voltmeter and measure. They are cheap, plus you probably have a friend who would lend you one.

irst, I noticed that there are only 2 conductors coming into the wiring box; black and white, and two leaving the box into the pump (blue-black) (photo 2). To me, a hot and a neutral says 115v.

There are times that running 240 through a white wire is permitted. There are marking rules, but they are not hard. You would probably do that if you convert from 120 to 240.

A single pole breaker would work in practice for 240, but it is definately not how you should do it. There are very serious safety and fire concerns. If that was done by somebody, you would need to fix that.

 

[mappley811]

With only a black and white wire, wouldn't one of them HAVE to be a neutral? Don't all circuits require a neutral line back to the panel? And to the point about a multimeter, what points would I be connecting the leads to to test the voltage? And would it have to be under load at the time of testing?

 

[Reach4]

With only a black and white wire, wouldn't one of them HAVE to be a neutral? Don't all circuits require a neutral line back to the panel?

No, and no. http://www.ecmweb.com/qampa/stumped-code-6

And to the point about a multimeter, what points would I be connecting the leads to to test the voltage? And would it have to be under load at the time of testing?

You can probe one wire on the left half of the switch and one on the right to measure the voltage between. You want to probe the wires from the breaker. You can determine the right wires by trial and error, or by seeing which wires don't go to the pump.

 

[mappley811]

Sorry if I sound stupid, but if the white isn't neutral, then where is the neutral for this pump?

 

[Reach4]

Sorry if I sound stupid, but if the white isn't neutral, then where is the neutral for this pump?

There is normally no neutral for a 240 volt circuit. Only special cases use a neutral, such as for a range that uses 120 volt light bulbs in addition to powering the 240 volt heating elements. But no neutral for a 240 volt compressor, water heater, or well pump. Only two hots. In Europe, and much of the rest of the world, there is normally no neutral run, even for a TV or electric razor.

Neutral in code is called the "grounded conductor". The green wire or bare wire, when present is called the "grounding conductor". The difference looks subtle initially, and the grounded and grounding conductors are actually connected in the main breaker panel. Commonly the grounding conductor is called "ground". The grounding conductor should not be carrying power current. A neutral for a 120 volt circuit carries the same current as the hot wire.

 

[mappley811]

Thank you so much, that clears up a whole lot. So I guess what I should do is open up the panel and see if the white goes to the neutral bar, or is double-tied to the same breaker as the black. Since it's only a single pole breaker, that's the only way it would be 240, right?

 

[Reach4]

Thank you so much, that clears up a whole lot. So I guess what I should do is open up the panel and see if the white goes to the neutral bar, or is double-tied to the same breaker as the black. Since it's only a single pole breaker, that's the only way it would be 240, right?

A meter at the pressure switch is easier. If you don't have a meter, one can be had for under $20. But for more money, you can get one with probes for voltage and ohms, but also with a clamp-around ammeter.

http://www.truevalue.com/product/14-Range-Analog-Meter/1508.uts or something similar can be gotten locally, or you could order.

 

[Valveman]

Or take off the back cover of the motor and see if the voltage selector is in the 115 or 230V position. My guess is it was changed to 115 volt and they just didn't take the 230V sticker off the motor.

 

[Reach4]

Thank you so much, that clears up a whole lot. So I guess what I should do is open up the panel and see if the white goes to the neutral bar, or is double-tied to the same breaker as the black. Since it's only a single pole breaker, that's the only way it would be 240, right?

The white would not be tied to the same breaker. To work it would be tied to some other hot line. If you tied it to the same breaker, there would be no voltage difference between the wires, so no power could be delivered to the pump. And when I say "work", I mean operate the pump. This is not to say that providing 240 as used in the US via a single pole breaker is ever right.

 

[Boycedrilling]

You do not have 240 volts without a two pole breaker.

You have two 120 volt buss bars in your panel. A 120 volt circuit breaker plugs into one of the buss bars and delivers 120 volts. Now you need a return path to complete the circuit. That is the purpose of the neutral wire. Additionally you have the equipment grounding conductor to ground the frame of the equipment. Now if you need 240 volts, you use a 2-pole breaker that plugs into both of your buss bars. This is giving you TWO 120 volt conductors that are 180 degrees out of phase. Each conductor acts as the return path for the other conductor. Thus no neutral wire is needed. An equipment grounding conductor is still needed regardless of the voltage.

So yes, you could use your existing romex wire to power the pump with either 120 volts or 240 volts. You would just need to use a single pole breaker for 120 volts and a double pole breaker for 240 volts. And you would need to have the correct wiring settings inside the motor. Sometimes it's as simple as rotating a switch. A 240 volt motor uses 1/2 the amps on each conductor.

A more important consideration for choosing a generator. If you use a 120 volt generator with your generator interlock, you would will only have power at every other breaker. You WILL need to have a 240 volt generator to provide power to both busses in your panel.

So yes, you can use a 120 volt generator if the only loads you want to power are on just one of the busses.

 

[Jadnashua]

FWIW, installing a generator, other than one where you plug in individual items right at the generator, can be really dangerous for anyone working on the power lines...it must be done correctly if you want to connect it to the panel, and that generally requires a disconnect/transfer switch so you don't mix power.

 

[Boycedrilling]

If you look at the photo of the electrical panel you will see that it is already equipped with a mechanical interlock for a generator. NEC approved.

 

[Traveller]

Or, you could just look in your breaker panel. If the black wire goes to a breaker, and its matching white wire goes to the neutral bar (where all the other white wires are connected in your panel) chances are 100% your pump is wired for 115 volt. Just sayin'......

 

[LLigetfa]

I cannot believe how much dialog there is on this. The picture clearly shows a single breaker for the pump. The only two double breakers are the clothes dryer and the range.

Anyway, why not just put a voltmeter on the line?

 

[Traveller]

I cannot believe how much dialog there is on this. The picture clearly shows a single breaker for the pump. The only two double breakers are the clothes dryer and the range.

Anyway, why not just put a voltmeter on the line?

Either way.

 

[mappley811]

Update time.

As many of you suggested, I tested the connection at the pressure switch and it's definitely 120V. Now the question is this; is there any reason I should go through the effort of changing over to the 230V configuration? I don't have an total amperage problem (just upgraded to 200A service a few weeks ago, thus the new panel and generator switch mechanical interlock). Are there any other possible downsides to running on 115 instead of 230? Increased wear on the pump, anything like that? If I'm correct, all it would require to convert to 230 is to move the conductors in the panel from the single pole breaker and neutral bar to a new double pole breaker, and then flip the switch in the pump to the 230V setting.

Edit: Also thank you so much for pointing out that I can only power a single bus with a 120V generator; I did not know that! I'll definitely be getting a 240V model.

 

[Reach4]

should go through the effort of changing over to the 230V configuration?

Not really. The pump would be using a tad less power from the generator, but the difference is probably not significant.

Do peel that " wired for 230v" label off of the pump.