Electric Motor Popping Breaker

Hi all. I don't know if this is the correct ng or not, but I thought I'd try here.

I have a pump with an electric motor. It has been running fine till a while ago it started poping the breaker. I verified that the pump impellor turns free and you can hear the pump start when you plug it in, but the breaker will pop in about 10 to 15 seconds. Any idea what can be causing this?

Thanks

Bert

Reply to
T. Bert Penney
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040805 2031 - T. Bert Penney posted:

The first thing to do is put an ammeter on the motor leads and find out how much running current the line has. Then see if the breaker is designed to handle this.

Reply to
indago

If it once worked properly then the most likely things to fail are the Centrifugal Start switch (if it has one) or the start/run capacitor.

Reply to
John G

This pump has worked fine for a few years now. It just started poppiing the breaker a couple of months ago.

Bert

Reply to
T. Bert Penney

This is a submersible pump (it is actually a sewage pump in my septic tank) so taking it apart is a last ditch effort :-)

Thanks for the suggestions. I will remove it and see what it looks like. BTW: Does it make any difference if the motor runs fine as long as there is no load but pops the breaker as soon as a load is placed on it?

Bert

Reply to
T. Bert Penney

i had a deep well pump blow breakers last winter... turned out the pump was fine, the wires had shorted (down in the well)

Reply to
Tim Perry

On Fri, 06 Aug 2004 02:44:46 GMT, T. Bert Penney put forth the notion that...

Check the easy stuff first... it could simply be a weak breaker.

Reply to
Checkmate

Do you have any evidence that the pump is actually spinning up? Hearing a 'buzz' doesn't mean that its actually turning. Even if the impeller turns free, you might have a bad starting cap or associated circuit.

I had a pressure washer pump with a similar symptom. The motor would just buzz but not turn. The rotor turned freely when rotated by hand. One of the starting cap. wires had come loose.

Reply to
Paul Hovnanian P.E.

That's possible. I do have another pump on that breaker now, but it is not lifting the effluent as high as the original pump, so I assume that it is drawing less power. I will swap the breaker out and see what happens.

Bert

Reply to
T. Bert Penney

I was thinking the same thing since my dog had chewed on the power cable for the pump. But, I replaced all of the chewed parts (shoulda replaced the dog :-)) but no change. I may have to bite the bullet and buy a new pump.

Bert

Reply to
T. Bert Penney

Yes. I removed the pump from the tank and, with it laying on its side so I could see the impellor, I plugged it in. It seemed to spin fine in free air. One thing that I didn't think to try - and I will be doing soon - is to lower it into the tank and try running it without it being connected to the hose leading out of the tank just to see if it will run under a small load. When you plug it in now, you can hear the splash of liquid moving in the tank until the nreaker pops.

Bert

Reply to
T. Bert Penney

On Tue, 10 Aug 2004 13:58:07 GMT, T. Bert Penney put forth the notion that...

If your breaker is close to being maxed out, it's not uncommon for it to hold the load for a few years, and then start tripping as the temper in the springs degrades. I remember one customer I had with a similar problem, but the breaker would only trip on real hot days. Once I replaced it, he never had the problem again.

Reply to
Checkmate

Assuming it once worked correctly, there are several possibilties.

Could be that your load has increased recently and the motor has to work harder thus drawing more current. I'd be inclined to measure the current draw and see just what it is. It could be the motor or starting caps are bad, or could even be problems with your wiring.

A bad or intermittant circuit breaker is also a remote possibility, but by far the easiest and cheapest to fix, so you might want to just replace it and see if the problem just goes away. Breakers that carry something close to full load for many years sometimes get more sensitive as time goes by.

Reply to
bob peterson

I have another pump in the tank now that only lifts the effluent about 7 or

8 ft and it works fine. The original pump has to lift it close to 30 ft to get the effluent to the septic field. So, last night, I disconnected the hose from the original pump to the field so that it would only lift the effluent about 6 ft. Then, I plugged the pump in and let it run. It lasted about 10 seconds and the breaker popped. Since there was almost no load on the pump during that time, I am beginning to believe that the pump motor has a shorted winding or some other malady. It does start and run fine; it just pops the breaker.

Bert

Reply to
T. Bert Penney

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