Run Capacitors

[stickboy1375]

Anyone off hand know what they think might be causing run capacitors to keep failing?

I believe this is the machine, it's single phase motor, i'm just not sure of the horsepower, thinking around 5HP to 10 HP Thanks for any input..

 

[micromind]

Are the run capacitors failing, or the start ones. The run ones are usually low mfd, under 100. Start ones are much higher, more than 200. A run capacitor can be energized continuously, start; usually 30 sec.'s max.

If it's the start ones, likely the start switch is not disengaging. There may be more than 1 start capacitor wired in parallel.

If it's the run ones, the first thing I'd do is see if I could get the capacitors in the same mfd rating, but higher voltage. I've seen this once in a while on IEC frame motors, very rarely on NEMAs.

The other thing I've seen is the capacitors that come on IEC frame motors are cheap (like any other IEC thing), and just don't hold up well. See if you can get something like a GE or other name-brand. They may not be made here, but the spec's are tighter, and they'll hold up better.

 

[stickboy1375]

I didn't know if a voltage problem could cause the problem or if it is the motor or just junk run capacitors...