New pump doesn't work

A bit of history; 20 years ago my submersible pump had been abused so
much by running dry and pumping heavily silted water that I bought a
replacement expecting imminent failure. My first submersible, a
Jacussi, had barely lasted 2 weeks.
Fast forward 20 years, the pump is still working but I am replacing the
spring water box it sits in for the 3rd time; Stainless steel this time
which I hope won't rust thru or rot thru have the termites feast on. I
decide to install the new old stock submersible while i'm upgrading the
rusty iron pipe fittings with brass.
First problem; the new pump is apparently 110 vac instead of 220 which I
have been using. Fortunately I had a circuit breaker that tripped
within seconds to alert me to the difference. Someone (me or Sears)
made a mistake 20 years ago. I rewired the AC supply to 110 volts and
tried again.
The pump doesn't work, not sufficient pressure out to get up to the
house (80 ft higher and 400 ft as the pipe goes). A clamp-on meter
showed 11 amps for a minute or so gradually dropping off to 8 amps,
which I thought was the initial surge of the pump pumping into the empty
pipe followed by settling down to normal flow. Not so, when I dumped
the pipe at the pump it seemed like only a few gallons atlow pressure.
I had been running the pump into an open pipe to flush out dirt and also
because the pressure switch was not controlling the pump and would not
shut it down at high pressure. If it were working properly the oipen
ended pipe should have had 80 ft head (40 psi).
It's difficult to trouble shoot because of the diatances between the
pump, the breaker box, and the outlet in the back yard. It's also
difficult (not impossible) to test the pump 'on the bench'.
Possibilities I'm thinking about;
* Maybe the brief 220 vac damaged the 110 vac motor,not likely since my
clamp-on shows reasonable current
*
Maybe I put the check valves in backward, not likely since there is
some flow and the pipe holds some pressure
* Airlock since the pump is almost horizontal, unlikely since the old
pump never had the problem.
*
Excess voltage drop in the supply wiring, maybe because 110 takes
twice the current and has 4 times the loss as 220. But I operate motors
over longer distances on the farm with no problem and a submersible is
inherently soft start since it starts against zero pressure. This is
obviously a loss of more than half the pressure & flow.
Any ideas ?
Reply to
Nick Hull
Loading thread data ...
I question the 110 VAC. All the submersible pumps I've seen are 220 VAc with a pump control box or capacitor box to start them. This is the kind of pump that goes inside a well casing. It will have three wires, normally red, black, yellow. You match the colors to the control box.
OTOH, if you may have bought a small flat bottom pump made to sit in the bottom of a pit. These pumps are often designed for very low head - maybe a max of 20 feet. It wouldn't be made to pump the 80 feet of lift you have. If this is the case, I would expect to see a trickle of water at 80 feet.
Karl
Reply to
Karl Townsend
110 volt pump will draw more current so a long distant if your wire is not heavy enough you will have more voltage drop at the pump end ...At 110 volt say your draw is 12 amp at 220 volt you might have 7 amp give or take a little at 400 feet you are going to have a 110 voltage drop probly not much left
Reply to
HaroldA102
Field procedure is to put a pressure gage on the pump ahead of a ball valve. Momentarily dead head the pump by closing the valve. Note the pressure. Also, throttle the valve to the projected gpm and pressure (direct the water into a bucket), and note the amp reading. Compare readings to performance tables for your pump. Motor winding resistance-specs can be found here
formatting link
Everything can be done in the shop if you like. Use a capped piece of 6" pvc for a tank. Make a simple manifold. Come out of the pump into a T, lower port to pump, upper gets the gage, side port to a 90, then a ball valve, output returns to tank. Good installers have a bench setup for this so that no pump goes into a hole without verifying that it's up to spec. If you do a tank test, you might have to lift the pump check-valve (assuming it has one) to get it primed before attaching the test manifold. Keep the testing down to a few minutes otherwise the water will get too warm.
Wayne
Reply to
wmbjk
Easy to check, slap a voltmeter right at the pump.
Jim
Reply to
jim rozen
You are right, I mistakenly assumed that it had to be 110 since it drew twice the current at half the voltage. Bad assumption, I pulled the pump out and it is 220. It also appears to have a locked rotor.
Anyone know a good way to free a locked rotor on a new submersible?
Reply to
Nick Hull
First thing that he needs to know - is it the motor or the pump that's locked? He'll have to separate the two units to see.
formatting link
If the shaft won't turn by hand, then the motor can still be used as a passable doorstop. The pump is series of plastic bowls and rotors enclosed in a relatively thin steel tube
formatting link
(pg 3). They can be fouled by a lot of sand or a little UPS handling. If it's stuck with sand, some careful working and rinsing might free it up. Testing will reveal whether pressure is still adequate. If not, they can be dismantled and rebuilt, but few bother.
Wayne
Reply to
wmbjk
The ohms seem to check, I'll test some more. The URLs should be real helpful so I get a picture of what's going on inside. I ass-u-me I can send an electric jolt to it dry when I try to whack it.
The pump has never been used but did arrive via UPS. Is sitting in a clean environment for 20 years conducive to lock up or just mishandling? I'm assuming the motor is locked up just from clamp-on current measurements and no output at all, I can't really see anything. I took out the check valve and can see a 5/8 nut that seems to rotate with fingertip pressure on the socket extension, but I'm not sure what the nut does. Might be the bearing, there doesn't seem to be any mass connected to it.
Reply to
Nick Hull
Once you separate the motor from the pump, it will be easy to see which is the problem by trying to turn their shafts with your fingers. If this is a standard submersible as depicted in the photos I pointed you to, then it's easy to separate the units. Remove the wire guard (long sheet metal thingy, usually has two screws on one end and little tabs on the other end) from the pump body, remove the intake screen (if it has one, perforated sheet metal around the pump to motor junction, usually held by two screws), and remove the four nuts on the studs that hold the units together.
Wayne

Reply to
wmbjk
Your pipe is blocked? M.K.
Reply to
markzoom
Is there any reason why the pump would be locked up? How tight are the tolerances? Nothing was ever put into the pump.
Reply to
Nick Hull
Based on what you've said, I wouldn't think so, but it's not worth speculating.
These pumps can usually tolerate quite a bit of crap ingested. But for all I know the thing came tight from the factory. If it was mine I'd take 30 seconds to remove the intake screen and try turning the shaft. If the shaft was anything other than free, then I'd spend the next three minutes separating the units. It's already taken whole lot longer to write about it than to actually do it.
Wayne
Reply to
wmbjk
I had already removed the intake screen, I can see the shaft but doubt I can find anything to turn it, it's pretty deep and inaccessable.
Reply to
Nick Hull
OK, I've got water back to the house to mollify SWMBO, now I'm seriously working on the bad pump. I pulled the motor off and it's free to turn but the pump itself seems to be locked up. I studied the SS Subs-04.pdf and removed the 2 small screws so I can unthread the end pieces. It's tight but I'm soaking the threads in Kroil now and will try to unscrew one or both ends. If I unscrew it a bit and the pump frees up can I just drill/tap another locking hole and run it? I have no idea what the torque specs should be. I'm guessing maybe it was tiightened up too much at the factory, does that make any sense?
From the pdf it looks like the plastic impellers (hollow?) are within plastic volutes so it might seem that the stack gets tightened in place and the impellers should not bind. Maybe they cold flowed in 20 years and oozed to interference with the impellers? Any help appreciated, I have never taken one of these things apart before.
Also, the first submersible that failed within 2 weeks (Jaccusi) is still in the barn. Any hope that that pump might fit the Sears motor?
Reply to
Nick Hull
After taking the pump apart from the motor, the motor seems to turn but a bit stiff, I did get it to rotate under power on 110vac. Will try 220 tomorrow.
OTOH, the pump is VERY stiff. At first I thought it was locked up but after I made an adapter I found I can actually turn the pump. I also tried pouring water thru the pump and was amazed at what little water flowed thru, barely a trickle. I would have thought what is essentially a centrifugal pump would have let a lot of water pass thru. I tried it both ways, same result. I have removed the built in check valve because I use the pump horizontally and the check valve only works by gravity when the pump is vertical.
It looks like the pump is so stiff the motor cannot properly start. Is it advantageous to put a lubricating solution in the pump, like soapy water, to try to ease the friction? My thinking is that if I can get it to start once it will 'wear in' quickly.
Reply to
Nick Hull
You have bad bearings or badly calcinined internal parts.
Gunner
Confronting Liberals with the facts of reality is very much akin to clubbing baby seals. It gets boring after a while, but because Liberals are so stupid it is easy work." Steven M. Barry
Reply to
Gunner
Since the pump has never been used I can't see how the internals got calciinted. The rotation is stiff but smooth and the bearings are new and unused.
Reply to
Nick Hull
This is the New one? Ah..mea culpa. Sorry. Sounds like someone may have screwed the pooch on assembly, or its bent.
You might indeed have good luck running it.
Dont some of those require cooling from the well water? Might consider sticking a hose in the end when running it.
I know a lot more about downhole oil pumps...chuckle...
Gunner
Confronting Liberals with the facts of reality is very much akin to clubbing baby seals. It gets boring after a while, but because Liberals are so stupid it is easy work." Steven M. Barry
Reply to
Gunner
You are using the control box right? How old is it? Do the caps look OK? Can you see the current to the start windings dropping off after a couple of seconds?
Wayne
Reply to
wmbjk
No control box, just a 2-wire motor.
I finally got it working. I separated the motor and pump and both were a bit stiff but neither was actually siezed. Apparently the friction was too much for the 1/2 hp motor to start. When the motor was separated, it could start itself so I let it run-in for a minute until the friction abated, as judged by how long it coasted after power-off (about a second).
Then I filled the pump with water (for lube) and turned it over with a wrench a bit, then re-coupled it to the pump. I mounted it upside down so I could pour water into the intake. It was loosened up enough that it started and pumped. Then I put the pump into a water-filled cooler (with the motor sticking mostly out) and powered up and got a good strong water flow, so I guess it's fixed. I'll put it into my water system next week, I'll have more help when the wife is gone (0 is more positive than -1).
Reply to
Nick Hull

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.