Start Capacitor?

[arminyack]

Hi,

So my 1981 Mark V has started to give me problems....

When I turn it on, the motor will start (although it hums) and run for like 5 seconds, the it pops the breaker. If I try to mess with the speed control at all during those 5 or so seconds, the breaker goes immediately. If I try to turn it on at any other speed but the absolute lowest, it will hum for about 2-3 seconds (but not turn), then pop the breaker.

I took the motor out, and sat in on the bench, and fired it up. It started & ran immediatley. I took the start capacitor cover off the motor, and noticed the foam piece the capacitor sits on was melted, and a good deal of of this melted foam was all over the recessed area on the top of the capacitor around the terminals. Could this thing have gone bad? I can no longer read the writing on the side of it, so i have no idea what to replace it with. Its a
1-1/8 HP motor (the brand I cannot remember) Can anyone tell me what the specs are on the capacitor for this?

[beeg]

More and likely it's KNOT the capacitor. WHEN was the last time ya cleaned it up and lube it?

[dusty]

Since the motor starts and runs, the likelihood of a bad capacitor is minimal. In fact, the motor is probably not your problem.

With the motor out, can you turn the drive shafts easily or is it difficult to turn. I would do this test by attaching the sanding disk and using it to spin the drive shaft. The resistance exhibited when doing this should also be consistent. It suspect that it is either stiff or presents an inconsistent resistance as you spin it.

As has already been suggested, a good cleaning and thorough lubrication may resolve your problem.

Has your unit been used regularly or has it been sitting unused for a long time.

[arminyack]

Its been sitting for quiet a while now. So far I've cleaned everything thing up inside with compressed air, but have yet to lube it.

When I turn the chuck with the motor in or out of the headstock, it has a lopsided resistance to it as it rotates.

[dusty]

A lopsided feel = inconsistent resistance through the rotation possibly = rubber belts with a memory (stiff) or spots in the rotation where the sheaves grab (drag) on something.

When you finish the lubrication and cleaning process, put the motor back and connect the drive belt.

If it starts, let it run for a while. This will flex the belts some and possibly minimize the belt stiffness.

I assume you are starting and running at low speed. If that is not the case and you are still having trouble at startup, use the sanding disk to turn the shaft and simultaneously turn the speed control to SLOW SPEED.

DO NOT CHANGE THE SPEED DIAL unless the drive shaft is in motion.

I'm not ignoring your question about capacitor specs. I just cannot answer your question. I also do not believe the capacitor is your problem.

While working on this sort of problem --- do not allow the motor to sit and hum. While it is humming - damage is being done to the motor.

[john_001]

The first thing I'd check is what else is on the circuit. When my father in law gave me his SS, he told me to fire it up and run it for a minute or two at least once a month or it would blow a circuit breaker. Based my experience, you need something pretty close to 15 amps to start the thing cold after sitting for a while. That's one full typical household circuit with nothing else on it. I ran a #12 wire with a 20 amp breaker directly to the SS and I've never had a problem since.

[arminyack]

Well, after a good cleaning & lube, it's running just fine now.

thanks for the tips!

[robinson46176]

Well, after a good cleaning & lube, it's running just fine now.

thanks for the tips!

Don't you love it when that happens...


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