Pulling up the Sub Pump?

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Old 03-11-08, 01:04 PM
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Pulling up the Sub Pump?

My Grundfos SP4" submersible pump burried at 160' depth (inside pipe) is blowing a 30-amp fuse. How difficult is it to pull up such pump/motor assembly? Can this be done by an average home owner or should I leave it upto a professional? Any advice/suggestion would be appreciated very much. Thank you gents.
 
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Old 03-11-08, 02:26 PM
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http://forum.doityourself.com/showthread.php?t=337231

Take a look at this...

Also, Humor me....Inspect "ALL" electrical connections between your well head and pressure switch. If your pump is indeed failed, you have only spent an hour or so of your time. If there is an "Overlooked" electrical problem, Youve spent the cost of the pump, and quite a bit of "BACKBREAKING", to end up in the same spot.
 
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Old 03-11-08, 04:33 PM
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Thanks for the reply and the thread.
I did check what I could for all the above-ground electrical items such as burnt or bare wires shorting inside/outside the Control box, pump saver, circuit breaker box, etc. However, after replacing the 30-amp fuse, as I was checking the voltage at the Control box by the well pump (to see if the well pump is getting the needed AC voltage), I saw intermittent small spark and a very slight smoke coming out from the open end of the 1" flex conduit pipe that contains 4 wires (Blk, Yel, Red & Grn) whenever the conduit got shaken (accidentally). The 4 wire-conduit run between the well pump and the Control box along or inside the stainless steel 4" pipe. Also, there is 120 VAC between the Blk & Grn/gnd, and Yel & Grn wires, but only 20 VAC between the Red & Grn - not sure if this means anything useful. After seeing the spark and smoke, I assumed the well pump needs to be pulled up and inspected. Is there anything else I should check?
 
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Old 03-11-08, 04:40 PM
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I saw intermittent small spark and a very slight smoke coming out from the open end of the 1" flex conduit pipe that contains 4 wires (Blk, Yel, Red & Grn) whenever the conduit got shaken (accidentally).
There is something shorted in the conduit....

IS this a 120v or 240v pump?

If we know the voltage, we can tell you what to expect between which wires.
 
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Old 03-11-08, 04:58 PM
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By looking at the manual and diagram on the Control box, the well pump appears to have a 240 VAC, 3-phase, 2-hp motor. So, it may be a wiring/conduit problem, not the pump/motor? Thanks for your help.
 
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Old 03-11-08, 05:19 PM
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Anything that sparks, or smokes, is not normal....Im convinced you have something going on in that conduit that shouldnt be. Whetehr or not you can access the "Offending area" without lifting the pump up out of the ground, is dependant on your setup, which I cant see. However, I doubt you would be able to see sparks and smoke at a depth of 160 feet, and likely the wiring is a straight line down to the pump. Look at the open end of the conduit for chafing of any wiring on the edge of the conduit.

I'm not exactly well versed on 3 phase motors,but feel free to go over to the electrical forum and ask about further testing the pump....There are quite a few knowledgeable guys there who can help you out with further testing.
 
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Old 03-11-08, 11:54 PM
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It sounds like beyond your current problems your setup gives little protection to the motor. Most likely you have some big problems and the pump needs to be pulled and most likely replaced.

With a three phase you would have 3 poles (each fused). The slow-blow fuse (fusetron) say at 10 amps would have protected your motor. 30 amp fuses at 240 volts allow much more current to flow and give little protection to your motor.

You may also have using a magnetic starter with heaters in it. Heaters are like fuses and should be sized to your motor.

If you are not familiar with motor controls and 3 phase you would probably be wise to work with a pump professional and a qualified electrician who is well versed with 3 phase controls and will fuse them closer than they have been.

I would say that a competent pump installer and a good electrician that knows how to protect motors can fix this and set you up for the future. 30 amps is way too high on a 2 hp, 3 phase, 240 volt motor. When problems come along the motor is usually fried before the big fuse blows.

Jim
 
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Old 03-12-08, 01:11 PM
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Thanks for the replies gents. I've been taking things for granted until the problem happened as usual... There are three 30 amp fuses (and one blew) when I moved into this house 3 years ago so I assumed they are the correct amperage. This is my first time looking at this well pump/motor/setup this closely. I just wanted to be educated more before calling the pro. Yes, I will ask the pro what amperage protection would be adequate for my setup.

I did not see any damage on any of the wires inside at the conduit near the opening nor saw any sharp edge or burr on the conduit edge that might cut any of the wires. I think the damage/fault is at much lower place from the ground level and the spark/smoke is traveling along up the (4) wires inside the conduit. I did see some slight moitsure/wetness on the wires inside the conduit so I know spark/electricity would use that as a conducting medium to come up.
 
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Old 03-14-08, 04:42 AM
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you say your pump is 3 phase...and you also say you moved into the HOUSE 3 years ago....are you sure you are dealing with 3 phase?...that is quite exspensive power supply and not normally put in houses (north america anyway)...i installed it 25 years ago in my little welding shop and it was very expensive then
 
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Old 03-14-08, 04:46 AM
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also (i am guessing here i am no electrician) a 30 amp fused 3 phase circuit would probably safely run aobut a 25 HP motor
 
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Old 03-14-08, 04:54 AM
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Originally Posted by billie_boy View Post
also (i am guessing here i am no electrician) a 30 amp fused 3 phase circuit would probably safely run aobut a 25 HP motor
that is a guess at 550 volts

at 3 phase 220 i think 7 HP would be closer
 
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Old 03-14-08, 09:11 AM
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are you sure you are dealing with 3 phase?.

I suspect he read the info from the control box and not the pump. If Im wrong, Im open to corrections, but "in another life" the contactor could be used to reverse a 3 phase motor. He has a 4 wire pump, with a "Start" and Run". Hmmm???

Im sure its possible, but three phase in a residence?
 
 

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