Electric Motor Not Starting (Page 4): Try a drop of solder to connect the wire to the conductor post. If the saw works, you're done.

jointerjohn

jerryc41 wrote:

I have an old Sears table saw with a 1-HP motor, a Craftsman KS55BXFS-352. When I throw the switch, it just hums - and not even a familiar tune.
The power wires are wrapped around bolts and held down by nuts. The nut for the black wire will not tighten when it gets down to the wire. It just keeps turning - probably stripped threads.

It's at least 40 years old, and buying a new motor wouldn't be practical. Any ideas?

Try a drop of solder to connect the wire to the conductor post. If the saw works, you're done.

jerryc41 Loc: Catskill Mts of NY

Indi wrote:

OK. Going along with Papa Joe's suggestion, maybe the blade is binding and needs lubrication. You could probably put some 3-in-one oil on the motor bearings and armature and try to free it up.

Nope. It all turns easily by hand.

tlbuljac Loc: Oklahoma

borrow your neighbors and when you return it, make sure you give him yours and tell him it worked fine yesterday and today it just got "OLD"......he will understand :roll: :thumbup:

tylerdan Loc: Bullard, Tx

Probably the starting capacitor needs replacing.

Bill Emmett Loc: Bow, New Hampshire

jerryc41 wrote:

I have an old Sears table saw with a 1-HP motor, a Craftsman KS55BXFS-352. When I throw the switch, it just hums - and not even a familiar tune.
The power wires are wrapped around bolts and held down by nuts. The nut for the black wire will not tighten when it gets down to the wire. It just keeps turning - probably stripped threads.

It's at least 40 years old, and buying a new motor wouldn't be practical. Any ideas?

This is a common problem with electric motors of all types. There will be capacitor on or near the motor. It will connect between the A/C wires. It will look like a cylinder with a wire coming out of each end. Many are silver in color. Be careful these are filled with a paste, and can be caustic. The use of the cap is to start the electric motor by charging up and then discharge a high voltage in the starter winding of the motor. This extra kick will start the motor turning, then the A/C voltage will keep it running. Replacement cost should be only a few bucks. Many times this is what goes bad in most electric motors used in saws, airconditioners, heaters, and furnaces. Good Luck.

B

George II Loc: Fayetteville, Georgia

jerryc41 wrote:

I have an old Sears table saw with a 1-HP motor, a Craftsman KS55BXFS-352. When I throw the switch, it just hums - and not even a familiar tune.
The power wires are wrapped around bolts and held down by nuts. The nut for the black wire will not tighten when it gets down to the wire. It just keeps turning - probably stripped threads.

It's at least 40 years old, and buying a new motor wouldn't be practical. Any ideas?

Jerry, more than likely it could be the start capacitor.
Good luck, compared to the newer ones this is something worth fixing.

The "G"

thom w Loc: San Jose, CA

Bill Emmett wrote:

This is a common problem with electric motors of a... (show quote)

Actually what the Cap does is cause a phase shift in the start winding. But if you like your explanation better OK

Dick Z. Loc: Downers Grove IL

jerryc41 wrote:

I have an old Sears table saw with a 1-HP motor, a Craftsman KS55BXFS-352. When I throw the switch, it just hums - and not even a familiar tune.
The power wires are wrapped around bolts and held down by nuts. The nut for the black wire will not tighten when it gets down to the wire. It just keeps turning - probably stripped threads.

It's at least 40 years old, and buying a new motor wouldn't be practical. Any ideas?

If the motor has a capacitor, The capacitor may need replacement. It may be best to take it to a shop for repair.

bunuweld Loc: Arizona

jerryc41 wrote:

I have an old Sears table saw with a 1-HP motor, a Craftsman KS55BXFS-352. When I throw the switch, it just hums - and not even a familiar tune.
The power wires are wrapped around bolts and held down by nuts. The nut for the black wire will not tighten when it gets down to the wire. It just keeps turning - probably stripped threads.

It's at least 40 years old, and buying a new motor wouldn't be practical. Any ideas?

Time to buy a new one. With a new motor, you may solve the humming, and next time have something else occur that may cause a serious personal injury. Infrastructures do age.

jerryc41 Loc: Catskill Mts of NY

tlbuljac wrote:

borrow your neighbors and when you return it, make sure you give him yours and tell him it worked fine yesterday and today it just got "OLD"......he will understand :roll: :thumbup:

I suspect he already did that with mine. :D

jerryc41 Loc: Catskill Mts of NY

thom w wrote:

Do you own an ohmmeter.

Yes, I do, but I didn't, this would be a good excuse to buy one. :D

How do I test the capacitor? It's 216-259 MFD.

thom w Loc: San Jose, CA

jerryc41 wrote:

Yes, I do, but I didn't, this would be a good excuse to buy one. :D

How do I test the capacitor? It's 216-259 MFD.

You can't test the value with an ohmmeter but you can see if it functions. When you put the ohmmeter leads on the Cap it should start by showing low resistance and you should see the resistance increase until it shows open or infinity. Also some meters actually have a capacitance feature and if yours does just follow the instructions.

jerryc41 Loc: Catskill Mts of NY

thom w wrote:

You can't test the value with an ohmmeter but you can see if it functions. When you put the ohmmeter leads on the Cap it should start by showing low resistance and you should see the resistance increase until it shows open or infinity. Also some meters actually have a capacitance feature and if yours does just follow the instructions.

Using a digital meter set to 20M, It reads a pretty steady 5.38, varying slightly. It stays at 5.37 - 5.40.

singleviking Loc: Lake Sebu Eco Park, Philippines

jerryc41 wrote:

As a last resort, I'll bring it to a place in town that repairs electric motors, but I don't want to put a lot of money into this. I have a good table saw, so this one was just for rough work. I could buy a new 10" table saw for less than the price of a new motor. I wouldn't spend more than $50 on this.

If it's an old motor, it might have capacitive start and then there's a capacitor located in the electrical connection box on the motor that might be burned out. Replacement of the capacitor is cheap enough as long as the windings of the motor or the bearings aren't trashed.

Some old motors also have carbon block contacts that wear out after time. Those may also be capable of replacement.

A good motor shop can rebuild the whole motor for you.

jerryc41 Loc: Catskill Mts of NY

singleviking wrote:

If it's an old motor, it might have capacitive start and then there's a capacitor located in the electrical connection box on the motor that might be burned out. Replacement of the capacitor is cheap enough as long as the windings of the motor or the bearings aren't trashed.

Some old motors also have carbon block contacts that wear out after time. Those may also be capable of replacement.

A good motor shop can rebuild the whole motor for you.

I haven't been able to find a similar capacitor online. It's 110v, 216-259 MFD, and it measures 3 3/8" long X 1 7/16" diameter.