Thread: Old table saw tripping the circuit breaker when try to switch on

hope its not the same as my Carbatec HTC 10HB where sparkie suspects its been overloaded and now heading for a rewind. I am hoping its something simpler but worst scenario is buy new motor (import $580 +) or new saw.

If it starts sometimes it may just need a service - armature clean up, new brushes and may as well do the bearings while you are there. My drill press started doing this and a new capacitor helped but it still needs a service.

Cheers

Bryan

Two most likely are
Dirty switch
Shorted capacitor or other component such as centrifugal switch - needs replacing

Less like
Dirty internals - - as suggested above a good blow out with a compressor
Shorted coils - not much you can do here.

Yes I would also first check the switch is clean and also visually check all electrical connections. (Obviously with the thing unplugged). You are looking for anything shorting out. It would be no surprise if clogged dirt or damaged wire insulation has caused a short.

Not to be pessimistic, but the way you described it made me think the rotor/stator coil has shorted or some component has failed. Unless you like restoring old machines, it might be time for an upgrade.

There is one other possibility that comes to mind.
Check the line plug, socket and any extension cord. A bad connection results in high resistance, and subsequent voltage drop.
The motor responds by drawing increased current resulting in breaker trip.


(also confirm it is over current causing the trip not earth leakage - hard to tell if it is combined rcd/cb)

Long and obtuse but maybe the reason.
OK, Mates. This is based on the North American electrical system. As it is FUBAR from your viewpoint as it is from our viewpoint is of your electrical system.

For residential, non-industrial electrical distribution in NA, the most widely distributed electrical is 220-230-240 volts. The actual voltage rating doesn't matter much as it is all within 10%. Then we do something that most of you will be thinking *W*T*F*. We configure this distribution similar to an A-B amplifier configuration where there is a center tap to ground. This is why most NA residential appliances are rated as 120 volts.

OK, yeah, I know it is a long way to Tipperary. In NA, there are many outlet strips sold, power point strips if you will. Almost all of these strips are purported to function as surge and spike suppressors. Electrically, these strips use various varistor values to implement the function. When a spike or surge occurs the varistor fails and shorts across its connection points. What this does is to trip the circuit breaker in the outlet strip. I have actually seen this in operation. I was in the shop and heard a sharp 'bang' followed by a second bang about 15 seconds later. There was an outlet strip on the bench plugged in, but nothing plugged into the strip. A small amount of smoke curled out of the strip after each bang. I know what you are thinking; "HOLY BAT POOP, smoke in a wood shop is terrifying.

I had an e-mail conversation with the technical staff at Underwriters Laboratory. I sent the outlet trip to the UL for analysis. After a few weeks I got an e-mail saying that the outlet strip did exactly what it was intended to do. Smoke????? No worries as it was contained.

OK, all of the male bovine excrement above may be the answer to your problem. In your table saw the power switch may have devices to protect the internal electronics from spikes or over voltages. If these have tripped, it could the reason for the circuit breaker tripping.

I had the same problem, which turned out to be a dud CB. Try plugging in something else that draws the same nominal current, eg a jointer or dust collector.

Just out of interest, is there a safety switch for that area? Is the circuit breaker tripping off but the safety switch carries on?