Dying Motor on Sears Table Saw?

[Michael]

I've had this table saw for at least 20 years. Lately, it's been tripping the breaker with greater frequency. I'm wondering if the motor is wearing out, or if I should check something else.

Thanks,

Mike

[The3rd Earl Of Derby]

Eliminate the source first?

Try something with more or less the same output on the socket,give it a couple of days before assuming its the saw.

[Michael]

Well, I have many other things running off that outlet. Occasionally, my 2 hp air compressor will trip it, but nothing else.

[Edwin Pawlowski]

Very likely the bearings are going and the motor is having to work harder trying to get up to speed. They can be replaced. Also possible that he bandsaw wheel bearings are causing the problem. Remove the blade and the wheels should spin freely.

[efgh]

Swap the breaker out for a bigger one. :)

[Leon]

Dull or dirty blade?

[Big Al]

Are you using an extension cord? If so, try a heavier one.

Al

[RonB]

If the compressor is tripping it too you might have a bad breaker. Do you have another tool that can simulate the same load as the saw but stay just within the breaker's limits? Breakers are much cheaper than motors.

OTOH, the motor in my old Craftsman started shooting craps at around 20 years. I had to replace the starting capacitor and internal switch and got another 5-6 years before it died. It never threw breakers unless I just bogged it down (easy with the 1hp motor).

Eliminate the breaker before you start looking for motors.

RonB

[JP]

[Art Todesco]

I would 1st try a new breaker, that is, if the saw, once it does get going, works ok. Or, flip flop the breaker with another one of the same size in the breaker box.

[RonB]

Mike: Shhhhh. Just between you and me, the local protectors of the newsgroup don't care for crossposters. Frankly I could care less, within bounds.

RonB

(I just noticed my outbound had two addresses)

[CW]

So you do care.

[Jim]

First of all, you need to eliminate the breaker as a source of your problem. Breakers loose a little strength every time that they trip. Hence, over time, they will trip at a much lower current level.

Testing the motor is not a simple matter. I suggest you take it to a motor repair place where they have tools adequate for the testing.

Jim

[todd1814]

I second this. My craftsman is 45 years old and occasionally starts throwing the breaker. Cleaning out the motor and adding some oil eliminates the problem for a year or two.

[No]

No one mentioned this, or asked these questions.

Is it a 15A or 20 A circuit? What does the amperage draw on the motor label read? What else is on this circuit? Add it all up. It could be you just have an overloaded circuit. Have you added something new recently?

[George E. Cawthon]

Have you checked to be sure that the the motor pulley turns free? How about the saw blade arbor? Have you blown the motor clean with a compressor?

[Joseph Meehan]

If it has been tripped a number of times, the breaker is likely weak and needs to be replaced. I would suggest that you should consider a dedicated circuit as it appears you are overloading that one.

[Joseph Meehan]

Please don't use that joke, there are far too many people who would not notice the happy face.

Don't replace a breaker with a larger one unless you have verified that the entire circuit will be able to handler the current and still meet code.

[LRod]

Too little information to really diagnose positively, but electric motors don't usually "wear out" slowly. When they fail, it's more in the nature of sudden, catastrophic, and terminal.

The bearings might give out slowly, but normally you would have fairly obvious symptoms which you have not reported, mainly noise or a rough or gritty feel when turning the arbor by hand (unplugged! of course).

Given that the motor is likely no more than a 1½ HP (typical for a home contractor type saw, even if it is a Sears and says more), and even wired for 120V and even run on a 15A circuit, it isn't likely to be tripping breakers with normal operation unless something else is going on (like additional load on the circuit--dust collection--or bogging down on cuts a lot, etc.). But again, not enough information.

My first suspicion would be dust, especially after 20 years of use. I'd check the on/off switch, the centrifugal switch, even the capacitor. Blow it out thoroughly with compressed air and see how it does.

Although the breaker might be the problem, and it's worth replacing for relatively few dollars, if you want to try it, they don't usually lose their effectiveness with just a few dozen trips--hundreds, maybe. What's your realistic trip count?

Here's a tip from troubleshooting 101: have you added anything to the circuit that didn't used to be there, like a dust collector? It's easy to forget conditions that have changed since the last known trouble-free period. In any event, what else is on the circuit?

As easy as that motor is to dismount from the saw, try taking it to a motor shop and get a diagnosis from them. Might cost you $30 or so, but you'll have a far more definitive answer than you'll get here.

[keith_nuttle]

I have an old Craftsman table saw of about the same age (1968). Mine started to give me trouble several years ago. I took it to a small motor repair store. They cleaned the ancient sawdust from inside of the motor and oiled it. It has worked fine ever since.

The reas> JP wrote: