Pump drawing high amps; what to do?

Discussion in 'Pumps and Tanks Well Forum & Blog' started by Bo, Jun 30, 2009.

  1. Bo

    Bo New Member

    Messages:
    6
    Hi all, glad to have run across this forum while searching out info on how what to do about a problem. Here's the run-down:

    Pump/Well Info
    Dempster M200 2HP

    Well Depth: 764 ft
    Discharge Pipe Length: 600 ft ( not really sure if pump is at 560 ft or 600 ft )
    Static Water Depth: 350'
    Pumping Water Level: 475'
    There is also a MF260 pressure tank set at 40/60

    This pump is used solely for pond/irrigation of 1.5 acre site. It was initially sized to top of 75000 gallon pond and mixture of drip / sprinkler irrigation.

    The Problem
    Woke up on the 26th and pump control box had popped the reset switch. After doing a reset the pressure tank filled and pump shutoff as expected; yet after opening our pond valve to full the pressure switch turned on the pump just fine yet the reset switch would trigger prior it being shut back off.

    I took the box to the hardware store and tested both capacitors. The run cap showed that it might be bad, so replaced it and the problem still existed, so then replaced the whole control unit, and the problem still existed. Called the company that installed the well and they came out the next day ( a Saturday! ) and tested the grounds ( which looked fine ) and the amp draw. The amps showed steady increase from about 13 to about 20 amps. So according to the installer and everything I could find online we need to pull it to see if it is the pump or motor.

    Since the pump would run for periods of time if the flow stays low ( which works for drip irrigation ) we decided to wait to pull it until he had a replacement pump. From what he says the pump manufacturer has recently changed ownership and the have had problems with warranty replacements that are _still in warranty_ let alone out of warranty by 3 days. :eek:

    So he gave me three choices; either stick with the M200 or go to either of these::

    StaRite 2HP 10 gpm Signature 2000 which I've determined just would not work for the water we need.
    Air Motor AS12-300 3HP, which he states would require us to upgrade the controller and the wiring as well as the pump. I didn't find anything online about this pump, but must admit I didn't look all to hard since it would cost much more.

    Choices
    Since we live in an area with only one driller who normally services wells we don't have too many options. But the charges seem ( to my ingorant eyes ) OK.

    2 men - 2 Hr pull, 1 Hr bench, 2 Hr install, with new check valve ( $670 )
    If the bench test determines both pump and motor need replacing then altogether roughly $2500. If it is just part then roughly $1500.

    Looking online I found one M200 < $700, but no other prices. And calling a few neighboring towns around here got me an average of about 1700-1800 for the M200.

    What do you think, just replace the M200 with another or go up in size/hp?

    The biggest concern is that during the summer months the pond evaporates and leaks enough to have to replace about an inch ( roughly 4000 gallons ) a day. Is that just too much for the M200; our well guy said we should be fine with running the pump for an hour then leaving it off for a couple of hours. If we do that, then it would take about 4 hours ( 966 gal/hr @ 0 psi ).

    Any input or advice?

    Many thanks and sorry for being so long winded.
    Bo
  2. Waterwelldude

    Waterwelldude Well driller,pump repair. and septic installer

    Messages:
    303
    Location:
    Texas
    It sounds like the pump end is going bad. If your pump is older than 3 years, it is a better choice to change the hole unit, pump and motor.

    When you replace the pump, get one with a control box. If there is a voltage surge or it cycles to often, the capacitor can be replaced. On a two wire, the pump will have to be replaced. There is a big difference between a $20 capacitor and a $700 for a new pump.
    That is what I prefer to use here. We have some pretty good surges sometimes, with lighting storms or just a simple power outages.

    The two hp sounds like a good choice for what you are doing.


    Travis
  3. Thatguy

    Thatguy Homeowner

    Messages:
    1,459
    Location:
    MD
    How long did this increase take?

    If the voltage stayed constant then this extra power is either going into overcoming mechanical or flow resistance or heating the motor because of an internal defect.

    Find the root cause before you invest in a new system.

    If necessary have a motor rewind shop try to duplicate the symptoms using a Prony Brake and/or do an autopsy on the motor and give you an opinion.
  4. Bo

    Bo New Member

    Messages:
    6
    Yep, when originally installed we made sure to go the three wire, controller route due to the amount of lightning we get here in the Ozarks.
  5. Bo

    Bo New Member

    Messages:
    6
    The increase seems variable, from memory I'd say about 5 minutes. When testing today I started off opening the valve wide open and once the pressure switch turned on, left the valve wide open and it ran 11 minutes before popping the reset; a test an hour later popped the reset in 9, then another hour later popped it in 8. I then closed the valve until only 5 gpm was being pumped out and started the pump again; it would even go four minutes, and I tried several times.

    I don't recall the voltage fluctuating; and will make sure to have him test for that prior to pulling the pump. From what our well guy said he can bench test it here on-site using some equipment in his rig.

    I assume he will disconnect the pump from the motor and if the motor is fine at that point then we can focus on the pump; but if the motor is bad how does one rule out the pump too? Hook it to a different motor?

    Thanks,
    Bo
  6. Thatguy

    Thatguy Homeowner

    Messages:
    1,459
    Location:
    MD
    http://www.youtube.com/watch?v=5fIHVgK051U
    Florida gets a lot of strikes, too.

    "During the summer of 1993, not only were torrential rains pelting the Midwest (resulting in great floods), but for the first time since automated lightning detection networks began, the national lightning "hot spot" was located in Missouri-not Florida."

    If the time to trip is independent of the GPM I'd say it is the motor.
    I've never heard of a (pump) bearing having increasing friction (current increase) and then resetting itself (low current draw) and then increasing friction again. It almost has to be the motor or the supply to the motor having decreasing voltage due to a bad connection (and so the motor draws more current to keep up with demand).

    If the problem is inside the motor, running it in free air should have it tripping sooner because it won't have water cooling.
    I'd spend some bucks tracing the root cause before replacing stuff. The worst outcome is that you get a whole new system and the symptom isn't changed in the least. It's unlikely, but it still may happen.
    Last edited: Jun 30, 2009
  7. Bo

    Bo New Member

    Messages:
    6
    Thank you for the sage advice. That does sound like a pretty darned bad scenario to be avoided! If our well guy doesn't have the capability of testing the motor for a root cause what kind of shop would we take it to?
  8. Waterwelldude

    Waterwelldude Well driller,pump repair. and septic installer

    Messages:
    303
    Location:
    Texas
    You said they checked the motor for grounding. It showed good. You put a new box on. It did not help the problem. The pump end is bad.

    When they pull the pump out, the pump end will have blue coloring on it. The pump end is getting hot.
    Some of the impellers may have come apart or the bushing in the top of the pump end has broken.

    If your pump is a 4" pump, you will be very hard pressed to find anybody to rewind it. They are considered a throw away motor.


    Travis
  9. upper

    upper DIY Senior Member

    Messages:
    154
    Location:
    Fresno, CA
    Waterwelldude is right on.Go with a new one,don't take a chance that your relatives might screw you:D Upper
  10. Bo

    Bo New Member

    Messages:
    6
    WaterWellDude, thanks for the input.

    LMAO. Haha, very cute.


    Question
    Is it worthwhile to replace just one part of the unit if a cause to the problem can be found; would there be enough life left in the other part to make it worth keeping, or is that just something that has to be played by ear?

    Thanks again,
    Bo
  11. speedbump

    speedbump Previous member

    Messages:
    4,540
    Location:
    Riverview, Fl.
    Look at the difference between the labor and the cost of the materials. Keep in mind that about half of the cost of the materials is labor too. Then decide if you want to put a unit that is 4-5 years old in your well when the average life of the entire unit is 7 years. Not to mention the motor has been pulling high amps for some time now and that is a life shortener also.
  12. Bo

    Bo New Member

    Messages:
    6
    Ahhh, I was not aware of that at all. In that case it is a no-brainer.

    I had heard of people having pumps lasting 15-20+ years, and sure there is a difference from how they are used and workload and such; I just never imagined that the actual average would be that low.
  13. Thatguy

    Thatguy Homeowner

    Messages:
    1,459
    Location:
    MD
    Equipment Replacement Strategies can be complex, even without taking The Cost of Money and your inconvenience into account.

    Going with the numbers posted your choices might be
    ~$3 kilobucks every 7 years (replacement) or
    $300 every 0.7 years (maintenance?) or
    $600 every 1.4 years (?) or. . .
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