Hello,

Well I finally did it. I plugged a DEWALT tablesaw 110volts into the 220volts outlet on my transformer here in france. I caught the mistake after say 35 seconds... and the saw still seems to work OK.. but, it sounds a bit different. Is the motor really messed up? Why does it still seem to work? Will it eventually quit sooner than later? And is there a fairly simple way to repair it?
Thank you very much
Caroline

It's probably messed up.

1. Check the Capacitor rating. That component may have fried.
2. Windings would easily burn.

Shorted windings would have likely resulted from overheating. In escense, not repairable.

In the days of a global economy, the voltage of the motor may be changeable or may not be. Now is a good time to think of a 220 V replacement.

If you had asked earlier, I may have been able to come up with a way to prevent it.

It could have been simple.

A universal voltage power supply, with a rectifier, divider on the mains and a small comparitor that would have sounded a buzzer if 220 V was applied before the switch.
This would have worked if the saw was off when plugged in, It could have been made more failsafe too.

First of all, you should not have been able to plug a 110 volt item into a 220 volt outlet. Replace the 220 volt outlet with the correct outlet, then this will not happen again. You might be OK with the drill, nothing you can do now, use it until it goes bad.

I'm going to say no, you have not damage the motor. If you had it would not be running. I take it that you are running off a transformer converting to 110. I believe that Europe also uses a 50 cycle current as opposed to our 60 cycles. That would account of the different sound and would also account for a slightly slower motor speed.

Hk:

The poster said the "sound changed". 50/60 cycles would change the speed as you stated.
When a winding overheats, the windings can short. It may not cause a complete failure, but it could cause a difference in speed. Many motors are designed for 50/60 cycles.

Failures could be:
Motor: winding short
Capacitor, if used: if 400 V, it might be damaged. If 600 Volt, probably OK
Switch: Contacts could be damaged due to overcurrent. It's probably a HP rated switch and not likely.

Motors make weird noises when a winding shorts and they don't run smooth. Been there. Done that.