Need some advice on diagnosing a submersible pump

Discussion in 'Pumps and Tanks Well Forum & Blog. Water is life.' started by JohnnyQuest, Feb 12, 2009.

  1. JohnnyQuest

    JohnnyQuest New Member

    Feb 12, 2009
    Pittsburgh PA
    Hi everyone, great site here.

    I have a problem and I'm hoping you guys can give me some advice. This might be a long-ish post as I tend to ramble...

    A couple of months ago my well pump died. Not really sure why, guy who used to live here (my friend) said he put one in years ago, and it was a cheaper one, so probably just wore out or something.

    Anyhow, he had a spare one, as he had recently upgraded his well to a larger pump, so he brought that one up.

    We pulled the old one, hooked up the new one, sent it back down, and everything worked great.... for about a month.

    Then all of a sudden this one just quit working too.

    I've had a pro guy come out and check a few things, he put a meter on it to read the amps, and said that they were too high, which to him suggested that the motor was fried.

    I should mention that, at some point before the new(used) pump was put in, I had to replace the pressure switch. When I did, I wasn't paying attention, and got the type that doesn't kick off the power if there is no water coming up (I apologize for not knowing the technical terms).

    Shortly after putting in the new(used) pump, this pro guy noticed that, so I went the next day and put on the right kind of switch.

    Just mentioning that in case that may have fried the motor or something.

    Anyhow, so I plan on pulling it out this weekend, and was just wondering once I get it out, if there is any way to test it to see if the pump is actually bad, or if it might be something simple like a bad electrical connection.

    I mention this, because after doing a lot of reading on this site, I'm not sure that my electric connections at the pump were necessarily waterproof.

    When we hooked the new one back up, I just grabbed some el-cheapo butt-type connectors I had laying around, and sealed them with some shrink-tubing.

    So I was thinking that perhaps the connection eventually got water in it, which may be causing the problem ? Even if that is so, I don't know if that would have damaged the pump etc.

    So I guess my main questions are, how can I test the pump when I get it out, to see if it might still be ok, and would a poorly sealed connection down there be causing it not to work ?

    Here are the details of what I have going on, as best I know.

    - Well is in a concrete pit in my backyard, about 30 feet from the house.

    - There is no pitless adapter etc, the pressure tank, switch, everything is down in the well pit.

    - Pipe is PVC, probably about 200 feet or so, going to measure when I pull it this time just to know, no idea how deep the well and water level is.

    - The original pump was a 2-wire, 230V, 1/2 HP. I'm not 100% positive on the one we replaced it with, but I'm assuming it has to be a 2-wire same voltage, or it wouldn't have worked to start with (?). Just not sure on the HP, I think it's 1/2 HP as well. Don't know the brand name either, if that matters.

    - I tested the amps today on the line going down the well, I used the lever on the switch to force the contact points etc. One wire was reading about 5 to 8 amps when power was on, and the other was about 8 or 9 amps. If I put the clamp on the gauge in between the two wires, I was getting about 15-16 amps, I'm assuming that this was the sum of both wires (?). I'm pretty handy at fixing things but measuring amps etc is a bit new to me.

    - Also I tested the voltage at the switch, it was reading 250, I don't know if that is a problem, I always thought res. circuits were either 110 or 220, but there's a lot about electrical stuff that I don't know.

    That's all I can think of right now, if anyone has any advise I would be very grateful. Also if there is any more info you need please let me know and I'll do my best to find out for you.

    Thanks again in advance for all of your help, and for this site !

  2. PumpTech

    PumpTech Junior Member

    Feb 12, 2009
    Pump Technician
    I would test for a ground fault. A meg-ohmeter is best for this but you can get a reading from a ohm meter as well. You should read above 500k ohms if it is ok. However it will operate until you get to about 20k ohms to ground and I would not pull a pump that measured 100k or above until it completely died.
    You will test this at the p-switch where you took your amp readings if in fact it is a 2-wire motor. If not, you will have to locate the control box and test anyone of the pump wire to ground, then do the same on the power supply to the box. Another wards put one test lead from your ohm meter to the wire you want to test, put the other lead on a good ground source.
    However, if the pump is running and pulls 8-9 amps as you mentioned without shutting off in a few seconds, It is likely that you will need to replace it for other reasons then a ground fault. Off the top of my head you should be pulling about 5-6 amp on a half hp and if you did have a ground fault preventing you from having any water, you motor probably wouldn't run at all or only very briefly...
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  4. JohnnyQuest

    JohnnyQuest New Member

    Feb 12, 2009
    Pittsburgh PA
    Ok I tested the ohms this morning and here's what I found.

    Also, I'm not sure if I'm testing it correctly, so I'll try to explain what I did.

    I cut off the power at the fuse box. Then I disconnected the two wires going down to the pump, from the pressure switch.

    Then I put the neg lead to the ground on the pump switch, and the red lead to one of the wires going down the well. This gave me @ 900 ohms.

    Repeated for the other wire, also gave me @ 900 ohms.

    Putting the black lead on one wire going down, and the red lead on the other wire going down, gave me about 6.5 ohms.

    Not sure which way I was supposed to test it so I tried both ways.

    Don't know if this helps shed any light on anything, I'm still gonna have to pull it because it's not working and there's really nothing else I know that I can try from the top side.

    I will probably go later today and get a new pump, just to be done with it, but if anyone has any other thoughts I would def appreciate it.

    Thanks again,

  5. JohnnyQuest

    JohnnyQuest New Member

    Feb 12, 2009
    Pittsburgh PA
    Ok I got the old pump out today, it looks like it's in pretty bad shape, I forgot how rough it was when we put it in, I was pretty desperate that day.

    So, I just went ahead and got a new pump today, it's the same as the others, 2-wire 1/2 HP 230V, I'm sure it's not the highest quality but, I don't actually own the property so I'm not spending any more of my money than I have to (long story). And yes I realize, you get what you pay for, if it last for 2 or 3 years then that's fine with me.

    So tomorrow I'm going to go over all of the pipe and wiring that is out, and make sure everything is in good shape before I send it back down.

    I do have a few questions though... the wire going down with the pipe, is only two wires, one red and one black. There is no ground wire.

    The pump has two black wires, and a green ground wire.

    So my first question is, does it matter which of the black wires I hook up to the red/black pair ? I don't know how you would tell them apart anyhow.

    And also, what am I supposed to do with the ground wire on the pump, if I don't have a ground wire to hook it to ? Should I just tape it off and seal the end so no water gets in ?

    Finally, at the pressure switch, where my line from the house connects to the red and black pair going down... does it matter which way these are connected ?

    The house wiring is standard one black, one white.

    So should I do black/black and white/red, or black/red, white/black ?

    Sorry for all the questions, I'm just tired of fooling with this thing and want to do it right this time.

    Thanks for any input

  6. Waterwelldude

    Waterwelldude Well driller,pump repair. and septic installer

    Feb 11, 2009
    Well driller,pump repair. and septic installer
    Since the pump is 220 and the old one was 220.
    The color on the wires does not matter.
    The ground wire should be hooked up, but since you only have 2 conductor wire going down the well, it will be fine.

    Strip off about 2 or 3 inches of the green wire and rap it around the pipe, and tape it on good, or just cut it off.
    In most parts of the country, the wire must be changed to 3 conductor wire,(by law) so the ground can be hooked up.

    For years the pumps did not come with a ground anyway.

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