3 wire well pump , wired directly to pressure switch?

[Stanly Kristan]

Hello everyone! Im new to well pumps . I purchased one hell of a fixer upper and the first thing i noticed was the insane hydro bill! i run leds for all my lights so it can only really be traced back to our well pump. I have no info on the pump from the previous owner. All i know is that its a 240v 3 wire red/blk/ylw 12 awg. It runs off a 20 amp breaker. Pumps in my area are usually 300-400 ft down in a 6 inch pipe. What im confused about is it has no controller, He had it directly wired from the panel 120v to red then the next 120 runs through the pressure switch and over to the black. yellow is not even used. wtf? Could this be my power consumption? Does anyone know of a controller i can use without knowing my hp size. My house uses almost double the power a regular household goes through and were living in the dark.

 

[CountryBumkin]

Is the pump running a lot?

 

[Sponsor]

 

[Stanly Kristan]

i cant really tell since i dont have a current meter. it would come on i assume every time my tank lost enough pressure, since its just a smaller tank im assuming a fair bit. I read that one wire on the 3 wire pump is for starting and one is for running . could wiring it this way make it use only one of the options.

 

[Stanly Kristan]

Just turned the sink on and the pump turned on right away!!! Shit! Looks like i have abit of work to do to correct this. So heres another question. i bought a 26 gallon(100l) pressure tank, would it be worth it to also use an extra 20g tank i also have. It looks like im going to have to tear apart the system anyways and start from scratch so i might as well use what i have

 

[Reach4]

It is possible to determine what HP of pump is down there if you actually had 3 wires to a 3-wire pump. It would take supplying a DC voltage, measuring current of the flowing DC, and some voltage measurements.

Come to think of it, it may be that the pump was replaced with a 2-wire pump, and the existing wire was re-used. That would explain the pump starting each time. You could get a rough idea of that with just resistance measurements. If the yellow wire was grounded or the yellow wire was open with respect to the other wires, that would support that idea.

 

[Valveman]

Yeah I would suspect that you have a 2 wire pump, and they just used 3 of the 4 existing wires to hook it up. I doubt that a 3 wire pump would even run without a control box. Your tank maybe waterlogged. But it is not the fact that the pump comes on every time you use water, it needs to do that. A high electric bill from a pump would be because the pump is running when you are NOT using water, or if the pump cycles on/off rapidly WHILE you are using water.

A 26 gallon tank only holds 6 gallons of water. So the pump will still come on for every 6 gallons you use. If the pump is running when you are not using water, you probably have a hole in the pipe or the pump is worn out. If you don't want the pump to start every time you use 6 gallons of water, you need a larger tank or a Cycle Stop Valve to use with your small tank.

 

[DougB]

It is possible to determine what HP of pump is down there if you actually had 3 wires to a 3-wire pump. It would take supplying a DC voltage, measuring current of the flowing DC, and some voltage measurements.

Come to think of it, it may be that the pump was replaced with a 2-wire pump, and the existing wire was re-used. That would explain the pump starting each time. You could get a rough idea of that with just resistance measurements. If the yellow wire was grounded or the yellow wire was open with respect to the other wires, that would support that idea.

While not a pump expert... First get a DVM (digital voltmeter meter) and measure the voltage between the two 'hot wires' (red & black). See if you get 240. Then measure between red/yellow black/yellow - each should be 120v.

In order to control a 240 motor, with a single pole (one wire) pressure switch, you will need a magnetic contactor (relay) that is activated by the 120 volt circuit. The 120 volts 'pulls in the contactor', and your 3 wire 240 volts is switch by the 3 contacts on the relay.

This is just an exaple:

http://www.galco.com/buy/ABB/DP40C3P-F?source=googleshopping&gclid=COig1pji98sCFQqKaQod6kkO3w

 

[Stanly Kristan]

Thanks for the great tips, i have 3 wires going down to the pump but i never thought to consider that it might be wired below for a two wire pump. The previous owner half assed everything in this house so ive learned not to trust anything i see. My project for this rainy day is to see if i can drop a line down the shaft to guage its depth. I might just have to pull the pump. ill try to find somemore info and im sure ill be back

 

[Reach4]

My project for this rainy day is to see if i can drop a line down the shaft to guage its depth.

Use a steel weight -- not lead.

 

[Valveman]

Use a steel weight -- not lead.

Even then it will probably get stuck on the pipe or wire and not give you a good reading.

All 2 wire pumps have 3 wires. The third wire is just a ground, and it will work without it. It is very common to find a 2 wire pump with (red, yellow, black) three wires going down hole. I would have used the red and black for hots and the yellow for ground, but you never know what someone else might do.

You don't need to pull the pump or check anything down hole. Just test the pump to see how long it is running and how long it is off. If it is running even when you are not using water, there is either a hole in the pipe, the pump is worn out, or the water level is too deep for that pump. If the pump is not running and stays off when you are not using water, a house without irrigation should only use 5-7 bucks a month on electric for the pump.

 

[Jadnashua]

FWIW, while it might be better to break both legs of a 240vac circuit, breaking just one leg breaks the circuit, and the pump, even though it may have voltage on one side, has no path for current, so a single pole pressure switch will work to shut it on and off. I think that normally, they use a double-pole, single-throw relay for this, but a single pole one could work, but may not meet code. A DPST relay would be safer. Working on the pump, you should shut the breaker off anyways, and that would remove all power.

 

[Stanly Kristan]

More great tips!, Thanks guys! So I did drop a line down, I took a cork and drilled in a heavy screw with some fishing line , But it only went down 15ft and hit the top of something, im assuming the pump, I can hear the clank from the top. cork also came out wet. Dropped it a couple times from around the pipe with the same results.... 15 ft well? This seems crazy because I live uptop a hill above the city where it is known to have 300-400ft wells. Ive talked to a driller from the area who says my area is abit of an anomaly with shallow areas but 15 ft seems crazy. At this height would it be possible to pull the pump by hand? Id assume it would be a smaller sized pump.

 

[Stanly Kristan]

on a happy note my dads best friend is a professional driller so there going to come over tonight to give it a look. My neighbour says theres a artesian well near by, I wonder if I am tapping into this.

 

[Reach4]

But it only went down 15ft and hit the top of something, im assuming the pump,

With a mirror, shine the reflection of the sun down the well to see what you can see. It is unlikely that the surface of the water and the pump are both 15 ft down. With water 15 ft down, the pump could still be much lower.

There are things called torque arrestors that you could be bumping into. Also, you did not mention a pitless adapter. Do you see that above the water? How far down?

 

[Craigpump]

Yeah I would suspect that you have a 2 wire pump, and they just used 3 of the 4 existing wires to hook it up. I doubt that a 3 wire pump would even run without a control box. Your tank maybe waterlogged. But it is not the fact that the pump comes on every time you use water, it needs to do that. A high electric bill from a pump would be because the pump is running when you are NOT using water, or if the pump cycles on/off rapidly WHILE you are using water.
.

Nope, a 3 wire won't run without a control box. I've tried it in the shop, the motor just gets hot as hell.

 

[DonL]

It is possible to determine what HP of pump is down there if you actually had 3 wires to a 3-wire pump. It would take supplying a DC voltage, measuring current of the flowing DC, and some voltage measurements.

What is the formula used to calculate HP ?

 

[Jadnashua]

Approximately 746W=1hp, if that helps. Depending on the load, a larger motor that is idling, won't be pulling as many watts, but in theory, at max load, that's what the equilalency is.

 

[DonL]

Approximately 746W=1hp, if that helps. Depending on the load, a larger motor that is idling, won't be pulling as many watts, but in theory, at max load, that's what the equilalency is.

I understand P = I X E

But to check a AC motor with DC is what I do not get. That is just measuring resistance not current.

If you do not know the current it is hard to figure Horse Power.

Measuring the current takes the guess work out.

My guess is that that is a 2wire motor with a ground. The switch should be double pole.

 

[Stanly Kristan]

Well the driller wasn't a big help but he is going to ask around to see who drilled it. I also found out my tank was set for 20/40 but the pressure switch was 40/60. Unfortunately my main water shutoff before the tank started leaking a bit. It's set right against the wall. Are these valves rebuildable?

 

[Jadnashua]

I understand P = I X E

But to check a AC motor with DC is what I do not get. That is just measuring resistance not current.

If you do not know the current it is hard to figure Horse Power.

Measuring the current takes the guess work out.

My guess is that that is a 2wire motor with a ground. The switch should be double pole.

P also = E^2 * R, and you can use that to figure out what you need.