What's that gizmo across the contactor coil?

[jrlandau]

Hi All,

On a Bridgeport Series 1, attempting to turn the spindle on blows a fuse in the 120v circuit (Fu4, 6A). So I'm thinking I have a problem in the contactor or the switch, especially because the previous owner had problems with the contactor (he priced a replacement, but didn't replace it). Advice is welcome.

In particular, what is the device that is wired across the coil of each of those contactors, and how do you test it? The schematic uses a symbol I can't identify, looks like a capacitor connected to something represented by a rectangle!

Thanks,

Joe

[Al_The_Man]

The two likely hoods are Varistor or (R/C) resistor/capacitor snubber, my guess would be a R/C type, this is to suppress any back EMF spike.
If R/C type a test with a meter should show open.
The varistor should not be discoloured and show high resistance.
Post #2, http://www.cnczone.com/forums/genera...ion_error.html
Al.