Wiring question- finding ground wire

[930dreamer]

I want to test a well pump that hasn't been used in over twenty years. I have a generator with a 30 amp plug. The well wire is yellow 3 wire submersible and I can't get to the other end of the wire in the well head. Is the middle wire the ground?I'm sure I'll need a new pump but.....

 

[walta]

Do you have a Ohm meter?
Walta

 

[930dreamer]

Yes I do. This is a 240 volt set up.

 

[Bert_]

Is one of them green? What colors do you have? Commonly would have black, red and yellow plus green ground. Lots of old pump cable didn't have a ground, didn't need it when you always ran metal pipe.

 

[930dreamer]

No colors

 

[Bert_]

Do you know if it's a 2 or 3 wire pump? 3 wire would need a control box with a start switch and capacitor near the well head. With 3 unlabeled wires it could be 2 wire with a ground or 3 wire without a ground. 20-30 years ago it was not common for pump cable to include a ground, around here at least

It's hard to tell much of anything from that picture.

 

[930dreamer]

That's all that's left of the wiring, I couldn't get the cover off the well head.

 

[Bert_]

Call around to some local well service places. Chances are somebody will have a record of what's down there.

 

[TRWham]

I think this will work:

If you check continuity across each pair and find only one pair conducts, then you have 2 wires with ground. If all three pairs conduct, then either the motor or wiring is shorted or you have 2 windings. You could probably suss out which are windings by comparing impedance. The combination that gives you the highest impedance should be the 2 windings in series. If any combination shows 0 impedance, something is shorted.

 

[Norcal]

Older submersible pump cable did not have a grounding conductor.

 

[walta]

Label the wires A,B and C
Measure the resistance in ohms
A to B =?
A to C =?
B to C =?

If we assume the old pump has a single phase motor. The motor winding will measure more than 1 ohm and less than 20 ohms

The resistance from the 2 motor winding wires to ground wire should be greater than 1000 ohms preferably infinite.

Walta

 

[930dreamer]

A-b= 3.7 ohms
A-c= 17.2
B-c=14.3

Corrected

 

[Wrench97]

You measured b-c twice and got different readings?
Or is that meant to be a-b then a-c?

See this for control info since most likely you do not have 3 phase service it'll have a start capacitor in the control box making the wires Start, Run and Common> https://www.electricalonline4u.com/2016/12/submersible-pump-control-box-wiring-diagram.html?m=1

 

[TRWham]

A-b= 3.7 ohms
B-c= 17.2
B-c=14.3

Okay, it seems like the lowest impedance should be the start winding, and the highest is the 2 together, so the middle number should be the run winding. Once you correct your (presumed) typo, we can figure out which terminal is which.

 

[930dreamer]

Fixed it, I was drinking some Mt Dew.

 

[TRWham]

Looks like B is common, A is start and C is run.

 

[dogdog]

Yes I do. This is a 240 volt set up.

240 pump don't have neutral.... wouldn't you just identify the two hots ? the ground wire should not have any continuity or resistances between the two hot ?

the two hot in the motor should show some ohm?

 

[Bert_]

You definitely have a 3 wire pump. I will disagree with the others on the ohm readings. I would say A is run, B is common, and C is start. Start winding is always higher resistance. There is no ground wire.

It's probably a 1/2 or 3/4 hp pump, best to find out for sure though since you will need a control box for the pump and they are HP specific.

 

[TRWham]

I think Bert is correct that the run should be the lower impedance winding.

 

[930dreamer]

Pump is a Pumpco SSA 4-Inch Submersible Water Pump, which was installed by Jay Allen, J & J Pump, on April 4, 1984. I also have the Installation Instructions on the pump. I will copy this information and mail it to you. I'll check my numbers again Sunday.

My buddy sent me this pic of his well, it has the same wire w/red stripe?

 

[Bert_]

Pump is a Pumpco SSA 4-Inch Submersible Water Pump, which was installed by Jay Allen, J & J Pump, on April 4, 1984. I also have the Installation Instructions on the pump. I will copy this information and mail it to you. I'll check my numbers again Sunday.

My buddy sent me this pic of his well, it has the same wire w/red stripe?

Looks like a typical pump control. It has the start switch and capacitor needed to make the pump start. If the cable looks the same it probably is.

 

[wyliesdiesels]

240 pump don't have neutral.... wouldn't you just identify the two hots ? the ground wire should not have any continuity or resistances between the two hot ?

the two hot in the motor should show some ohm?

But it does have a start winding hence the 3 wires. There is no ground wire.

 

[Norcal]

But it does have a start winding hence the 3 wires. There is no ground wire.

Pump has been around for a while then if no grounding conductor probably 20 years or so since the grounding conductor was required, but hanging them off steel pipe is pretty rare now.

 

[930dreamer]

Can I test this well pump?

 

[wyliesdiesels]

Pump has been around for a while then if no grounding conductor probably 20 years or so since the grounding conductor was required, but hanging them off steel pipe is pretty rare now.

OP said it was installed in 84' so yeah 20+ years old...

 

[Bert_]

Can I test this well pump?

Probably the easiest way to test is to get a control box and wire it up. They aren't that expensive, <$100. Your ohm readings sound good for a 1/2-3/4hp pump. But even if the motor is good there is no way to tell if the pump is froze without trying to run it.