I bought a tool grinder with a 1/4-HP GE motor which is probably 50 years old. The motor runs on 115 volts at 1725 RPM. A thin belt connects it to a pulley on the shaft that holds the grinder wheel.
The grinder's bearings are bad. They provide a lot of resistance to rotation. I am in the process of replacing them. The resistance makes it harder for the motor to spin up.
When I turn the grinder on, it trips the GFCI in my shop. The GFCI is in a wall socket, not a breaker. If I remove the belt so there is no load on the motor when I turn it on, the GFCI does not trip and the motor runs.
What's the best approach to fixing this thing?
I have read that I can't test the windings properly without a megohmmeter. Is that true? I don't have one.
I was thinking a capacitor might be leaking current, but I haven't been able to find any capacitors. There is no capacitor on the outside of the casing. The motor has special rubber mounts that will have to be removed before I can disassemble it completely, and I am reluctant to do it unless I have to, because there is zero possibility that I can get replacements if I tear the mounts.
Thanks for any help you can provide.
The grinder's bearings are bad. They provide a lot of resistance to rotation. I am in the process of replacing them. The resistance makes it harder for the motor to spin up.
When I turn the grinder on, it trips the GFCI in my shop. The GFCI is in a wall socket, not a breaker. If I remove the belt so there is no load on the motor when I turn it on, the GFCI does not trip and the motor runs.
What's the best approach to fixing this thing?
I have read that I can't test the windings properly without a megohmmeter. Is that true? I don't have one.
I was thinking a capacitor might be leaking current, but I haven't been able to find any capacitors. There is no capacitor on the outside of the casing. The motor has special rubber mounts that will have to be removed before I can disassemble it completely, and I am reluctant to do it unless I have to, because there is zero possibility that I can get replacements if I tear the mounts.
Thanks for any help you can provide.