table saw tripping

[Paul Saffold]

I have a Jet contractors saw bought new in late 1990s. The date on the motor is 1995, 3450 RMM, 18 amp (listed 1.5hp).

It is under powered. I knew that when I bought it, but that’s what I could afford at the time but it was a huge step up from a 9” sears saw.

I have always had to take shallow cuts when ripping 8/4 stock or the motor would trip. Any 8/4 stock - pine, oak, pressure treated.

The motor reset is tripping, not the circuit breaker in the panel.

Lately it seems to trip more. Recently I was ripping 3/4” plywood to make an adjustable router circle cutting jig and it tripped again.

It is on a 20 amp circuit.

I clean the blades regularly. I was using a 50 tooth combination Freud blade, reasonably sharp. New blade on order just in case.

So, what say you guys and gals with experience with this? Repairable? I’m pretty handy and fix things myself. Or?????

[Frank Pratt]

Check the pulley alignment. Perhaps one of them has wandered.

[Zachary Hoyt]

I had a DeWalt 733 planer that would trip the overload protection on the motor all the time. It was very annoying. Finally I decided that since I had bought it for $120 and already gotten that much use out of it I would just remove that part and connect the wires together. It ran like that for about another 10 years, and was much more useful. When I decided to replace it the motor was still good, but the belt had begun to jump off the pulleys and I didn't want to mess with it when I had a few hundred board feet of hardwood to plane. I would try bypassing the overload and see what happens. It sounds like it may have been defective from the start. You don't have much to lose, and may have much to gain, potentially.

[Doug Colombo]

I had an old sears ts that had the same issue. Bottom line was that the thermo breaker on the motor went bad and would trip under small loads that is handled in the past with no issue. You could try to use a thin kerf blade (if you haven’t done that yet) to reduce load on the motor. If it still trips, you can get the motor breaker replaced. My saw was from the early 50’s and the way and type of breaker that was used then, replacement was going to cost more than a new motor, so I just bought a new Lesson motor. Not sure which would be the most cost effective way to go with your motor but worth checking out the costs.

[Lee Schierer]

My saw is a 1980's craftsman with a 1 Hp motor. I can easily rip 2 x 4 lumber on my saw using a dedicated ripping blade without tripping the motor thermal protector. It isn't as fast of a cut as I would get on a 3 or 5 hp saw but it does the job. A few thoughts:

1. Does the saw have start and run capacitors? If so one or both could be bad.

2. Is the motor too hot to touch right after the motor reset trips? If not the thermal protector is probably bad.

3. When ripping try using a 40 tooth ripping blade instead of the combination blade. They do work better than combination blades particularly when making heavy rips in 8/4 lumber. Perhaps your combo blade is dull or dirty from accumulated sap.

[Bill Dufour]

Any small gauge extension cords will cause voltage drops and motor overheating as it draws more amps to make up for under voltage.
Bill D

[William Hodge]

I had a saw with a key way on the sheave on the arbor. The set screw on the keyway loosened, and the key slid out and was rubbing on a casting at 3450 rpm or however fast a saw blade spins. The casting has a nice groove worn in it now. The thing could have caught fire. I noticed, because the saw blade slowed down faster than normal when I shut the power off. I never tripped the breaker or reset on that saw.

I suggest opening up the saw and seeing if all the moving parts are moving as they should. I would take the motor out and screw it to a bench, and see how it runs. If you don't find anything, take the motor to an electric motor shop, and have it checked out.

As stated above, the power supply to the saw should be 12 gauge wire, short runs, in good condition. The outlet needs to be be the right voltage and amps.

[Cameron Wood]

+1 on Zachary Hoyt's approach- eliminate the thermal reset. Most motors don't have one.

[Warren Lake]

if you take the thermal overload out you will probably burn out the motor.

Sears had some bad thermal overloads, had a radial for cross cutting rough. Waste of time. Ended up using the skill saw and no more issues.

[Cameron Wood]

if you take the thermal overload out you will probably burn out the motor.

Sears had some bad thermal overloads, had a radial for cross cutting rough. Waste of time. Ended up using the skill saw and no more issues.

Of approximately 15 stationary motors in my shop, I think one has a thermal overload. None of them has burned out.

[Warren Lake]

His saw burned cause I took the thermal out. Thermal was there to protect it.

[Richard Coers]

Definitely something wrong with the overload switch. I don't think they would have that many cycles in them, so all those trips over the years may have been the culprit. If you consider how fast you can rip plywood with a hand held saw, that saw should fly through plywood. Do you have enough money now to upgrade? I'd say time for a real table saw.

[Zachary Hoyt]

Sears made some pretty poor quality motors too. I burned up 3 or 4 Craftsman table saw motors in older saws that I bought, and then I finally bought a used Delta contractor's saw and it was much better and lasted till I sold it after buying a Unisaw 10 years later. The OP has a Jet table saw so I would think the motor would be better quality. Might as well take the overload protector out of the circuit and see if it works better. If the motor does fail a new one can be bought, or a new saw, but there's no point replacing the saw until then unless the OP wants something different anyway.

[Ken Combs]

Another vote for a thermal overload issue. I wouldn't jumper it, but replace it with a new one. While in there be sure it isn't packed with dust, lots of them are and restricts the airflow.

Also, check the supply voltage under load just to be safe. 50T combo blade is not a good choice for 8/4 stock of any kind.
,
1.5 HP should be fine for most home use. I've used 1 and 1.5 for years with no issues like that. I have a ancient Unisaw with a 1hp bullet motor that is a beast, for a 1hp.

[Frank Pratt]

Of approximately 15 stationary motors in my shop, I think one has a thermal overload. None of them has burned out.

You sure about that? Many motors have overloads that are entirely internal and you can't see them from outside the motor. The kind of motors that are permitted to not OL protection are low power, low torque type that will just stall out without overheating. 3 phase motors do not have integral OL protection because the starter provides that. Some have a sensor embedded in the windings that connect to the starter coil for motor protection.