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Join Date: Dec 2007
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Electric Motor

05/12/2012 12:08 PM

I have a pool pump 1hp, I haven't used it in about 5 years or so. Its a hayward pump. I have it wired for 120 volts. I pluged it in with out any water going through it and the motor started fine and ran fine. I put the suction hose in a pail of water and it pulled the water out fine. Im going to use it for a small gold fish pound, I hooked up the suction and the outlet pipe. The bottom of the suction pipe to the pume is about 6 foot lift. the out let pipe is only about 2 foot higher then the pump. I primed the pump and pluged it in and it worked fine, Then i shut it off, then I started it up again, worked fine , Then started it again and this time the motor started to start and then slow down, go fast, then slow down, it seemed like the capacitor is no good. Could that be the trouble? oh I only had a cheap extention cord 50 foot.Cord looked like it was good for only 8 or 10 amps. also the pump could be wired for 220. and it did work when i put it under my bench.{i think} lol

Thanks for any replys.

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#1

Re: electric motor

05/12/2012 12:22 PM

Does the motor have a nameplate?

My 1 HP pool pump is rated at 14.2 AMPS at 120V.

The extension cord is too small/long.

That's all I know.

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#2

Re: electric motor

05/12/2012 1:34 PM

Another bit of general information (tho' it doesn't have much bearing here) is that the height from the bottom of the pipe to the pump is irrelevant - the important figure is the height from the water surface to the pump.

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#3
In reply to #2

Re: electric motor

05/12/2012 1:37 PM

Good point. My pump only has to lift water about a foot and a half.

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#7
In reply to #2

Re: electric motor

05/13/2012 2:04 AM

Not applicable here, but a centrifugal pump can only LIFT cold water about 15 feet (above the level of the water). The issue is a combination of NPSH and vapor pressure of the water.

At 15 foot lift, the suction is nearly 14 mm mercury- near the boiling point of 62F water.

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#4

Re: Electric Motor

05/12/2012 2:25 PM

If the capacitor was no good the motor probably wouldn't start, it could be engaging then failing to disengage, if this is the case it will burn up soon enough as the potential relay is failing....It's pretty hard to troubleshoot something that's not properly installed, with no amp readings or anything really....The motor could just be picking up load and then the empellor cavitating due to air in the line...or it could have some bugs or moisture or surface deterioration on the copper shaft contacts or the brushes might be worn making intermittent contact....there could be a wire broken in the supply voltage making weak contact....The extension cord may only be rated at 8 amps but would still supply 14 amps until it burned up...If you have the time, inclination, tools and skill necessary, I would check the brushes first and amp draw of the motor, make sure I had a good and adequate electric supply....Then if nothing found, take the motor apart and clean the contacts and wiring connections...

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#6
In reply to #4

Re: Electric Motor

05/12/2012 10:59 PM

Look in the water intake, if the pump has been sitting it may be full of insects/dirt/dust. Some pumps have three or four screws on the intake holding a small grate.

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#5

Re: Electric Motor

05/12/2012 2:32 PM

My OOPS, Order Of Probability Sequence:

  1. As already said, cord too long / current too high for the cord. 1HP at 120V is going to need at least a 12ga cord if 50ft long. "Cheap" cords are often only 16ga, good for about 10A. So you are causing a voltage drop when starting and so there is a severe loss of torque. As soon as it almost gets to speed, the water starts to flow, which increases the load on the pump and exacerbates the voltage drop, which keeps it from fully accelerating, repeat to destruction.
  2. Electrolitic Caps on the motor dried out after sitting un-powered for 5 years, worked a few times and then popped.
  3. Spider webs / corrosion in the centrifugal start switch (if any) due to neglect. If it was a pool pump it was probably a PSC motor so there wouldn't be a centrifugal switch, but you never know without looking.

By the way, 1HP is WAY over kill for a goldfish pond, unless you want to make fish meal by sucking them in!

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#8

Re: Electric Motor

05/13/2012 5:50 AM

hello conntaxman it seem to be need to install a (foot valve_) on the end of suction pipe so the water will not full it back down ward that is the only promblem in your water pump slow and fast start , note the cord you are using is no problem in it ! only foot valve or non return valve need ,

hope this will make you happy !

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#9

Re: Electric Motor

05/13/2012 8:30 AM

Standing around for a long period of time has siezed a bearing with corrosion.

Just a thought!

Stu.

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#10

Re: Electric Motor

05/13/2012 10:14 AM

I'd look first at the suction pipe and strainer basket (if equipped) and see it it is clogged or partially clog with debris. Also, you may be experiencing some sort of "air binding" along a portion of the suction pipe, possibly even at the strainer.

The Hayward pool pumps (specifically for the aboveground pools) have a flooded impeller eye because the pool water level is always higher than the impeller eye by a couple of feet. If you don't have that situation you can entrap air in the suction line.

I'd use a sewage submersible pump in your case, one that is capable of passing a 1" sphere.......Hydromatic, Meyers and Goulds are very good ones.

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#11

Re: Electric Motor

05/14/2012 1:56 AM

an extention cord is too light to run a 1hp motor.

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#12

Re: Electric Motor

05/14/2012 4:36 AM

If its cap start, cap run motor, maybe the run cap is no good, the motor stalls and then goes back to start mode again on the cf switch etc etc??

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#13

Re: Electric Motor

05/14/2012 9:58 AM

I'll bet there is a fish stuck in the intake...

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#14
In reply to #13

Re: Electric Motor

05/14/2012 3:14 PM

"I'll bet there is a fish stuck in the intake..."

As I said, if there isn't yet, there probably will be soon with a 1HP fish pond pump. But most likely unless it was too big for the intake opening, it would be chopped up into food for the remaining fish...

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#15
In reply to #14

Re: Electric Motor

05/14/2012 3:20 PM

Yes a Sushi pump.

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#16
In reply to #15

Re: Electric Motor

05/14/2012 4:21 PM

Well I guess without the rice, it would be a Sashimi pump?

Mmmmm... it's lunch time here, gee I wonder what I'm going to go get now?

Oh! Sushi!

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