Grizzly G1066 Drum Sander

[Brian Peters]

Good evening guys. Trying to help a friend trouble shoot a late model Grizzly (G1066) 2 drum, drum sander. The problem I believe is the centrifugal switch on the motor and the capacitor. I'm replacing the switch and it's respective contact plate but I want to get the correct replacement capacitor. I have mixed information on the correct values and I don't trust that the one in there is the original. It's a 590-708 microfarad, 125V cap that was in there, but Grizzly says it's 600mfd, and some of their 5hp replacement motors use a 400mfd cap. I'm opting for the 250V rating on the capacitor, even despite the fact that grizzly seems to use under or closely rated start capacitors. (220v supply to a 125v rated cap, even for a short time isn't a fantastic idea, even if it works), but wanted to know if anyone had this machine could check the start capacitor value on capacitor itself, I would really appreciate it. Thanks.

[Mike Schuch]

I have replaced a good number of starting capacitors and the value does not have to be exact. 590-708mfd means the actual value will be somewhere between 590mfd and 708mfd depending on the voltage and temperature. 600mfd will be fine. I also use capacitors rated for higher voltage than original for extra insurance. I figure if I am replacing the cap the original voltage rating wasn't high enough or the cap wouldn't have blown. As motors and machines get older the friction increases and current draw and voltage spike through the cap on startup get bigger.

The higher the mfd the higher the voltage spike and the faster the motor will get up to speed. I am not an electrical engineer... these are just what I have learned by observation.

[Brian Peters]

Thanks Mike for the input. I too don't like the lower ratings, typical overseas, good enough as long as it doesn't immediately blow up. Anyone that actually has this machine could check it would be great.