Sometimes, when I start my pool pump motor, it turns for a few
revolutions, then pops the circuit breaker. Other times, it starts
and runs normally. This is not a case of clogged skimmers. Before
the breaker pops, I can run the electric light in the pool shed--the
breaker only pops when I switch the motor on.
The motor is ju-u-u-st out of warranty --installed May '09. Before I
spend $370 replacing it I want to be sure it's the motor and not some
electrical glitch in my wiring, or a problem with the pool pump. Any
You could check the voltage to the motor at startup. I would take the
motor apart and see if the.... don't know what it's called... the
centrifugal switch and contacts are working properly. It is what powers
the start winding then with speed it switches to the run winding.
Probably the centrifugal switch..........
I've been confronted with this situation twice; once about 40 years
ago and a couple years ago.
Different motors, different pools (thus completely) different setups.
The first case a lizard had crawled into the motor at night and his
tail got into the swtich.
The second time it was just that the contacts were a bit burn &
I showed my neighbor how to dis-assemble the motor and run some crocus
cloth over the contacts.
Blow the mechanism and re-assemble.....been working fine for a couple
You only have to expose the switch, you don't have to remove it from
the motor rotor.
The contacts can be easily tuned up in place. The switch is spring
loaded so I recommend against messing with the switch assembly.
Just open the contacts slighty to get the point file or some crocus
cloth between them.
Your motor is new so that adds a bit to the mystery. But I've had new
motors be problematic too (case misalignment that caused excessive
I'd try some compressed air into the end of the motor before a
Let us know how it works out.
Or the starting capacitor. I'd suspect either as a possibility.
Also, you could have a weak breaker. Try another breaker if there is
one to swap to (or just buy a spare, they're usually $5 or less)
Is the wiring heavy enough?
Of course there could be crud in the motor causing it to bind up a
Did you oil the bearings? (unless they are the oilless type).
PS. A motor shop can test capacitors....
Don;t know how many hp this motor is, but a typical 1 hp pool pump
motor should cost about 1/2 that price. Besides the suggestions
already made, you could take the motor to a local electric motor
I often see good prices in surplus electronics catalogs. This is old,
don't know if it's still available. They may have other different ones
3/4hp explosion proof motor $99.99 (A.O. Smith)
I have a 220V compressor that would cycle well for awhile, then randomly trip
the breaker. It finally quit starting. Turn on the breaker, and it would just
buzz loudly. I cleaned the starter switch contacts - no help. Tracked down the
bad starter capacitor and replaced that, both problems seem to be solved. $13 at
Grainger for the part.
You can check the capacitors with an ohmmeter. A good one will show a gradual
reading rise from when you touch the leads to the capacitor. Reverse the leads,
and the reading goes negative, then gradually climbs into the positive readings,
until it finally reaches the bleed resister value, or off scale if no resister.
A bad Cap will change quickly if open, it not at all is shorted.
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