Need capacitor advice for Unisaw

[Dan Hahr]

Evening, everyone. I have a delta X5 Unisaw that just blew the start capacitor. I have another capacitor on hand but the microfarads are higher. Also the one that blue appears to have a resistor between the contacts. The one I have does not. The one off of the saw is 260 to 311 µF. The one I have is 400 to 480 µF both are 250 V. If anyone can provide some advice that would be great I’m trying to finish up a project before the morning .

Thanks, Dan

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[Paul F Franklin]

You can probably get away with for the short term in a pinch as long as you're sure it's just a start capacitor. It will increase the starting torque and starting current; it's possible you may pop the breaker, but unlikely since it's only marginally higher in capacitance. I'd replace it with the correct value when you can get it.

[Bill Dufour]

If this is running on 240 volts that capacitor is too low a voltage . That is why it blew. it should be at least 370 volts fora. 240 RMS volt main power. 187 Volts for 120 RMS volts.
The bleed resistor is not really needed but you can shift it over to the new cap if that makes you happy. Or I would leave it off and just short the cap to ground if I ever had to open up the wiring again.
Bill D

[Dan Hahr]

If this is running on 240 volts that capacitor is too low a voltage . That is why it blew. it should be at least 370 volts fora. 240 RMS volt main power. 187 Volts for 120 RMS volts.
The bleed resistor is not really needed but you can shift it over to the new cap if that makes you happy. Or I would leave it off and just short the cap to ground if I ever had to open up the wiring again.
Bill D

Thanks Paul; I'm going to try the spare and see how it works.

Bill, I'm confused as to how these ratings work as I see so many different combinations of uF and volts on different motors. I also have an X5 Planer and it has a 3 hp motor. I pulled the caps to see how they compared and it seems that one of them was actually a 125v 500uF cap. It was the bigger of the two and not sure if it was starting or run capacitor. Anyway, they were the original caps, and have run well for about 10 years so I'm guessing they are the right ones for the motor. I just don't know how far off you can get with the numbers before bad stuff happens to the motor itself.

Thanks, Dan

[Bill Dufour]

Voltage the higher the better. No need for anymore then 400 volts. The uF should be close to the original within 10-20% should be oaky. Electrolytic caps will fail over time regardless.
Bill D

[Dan Hahr]

Checked the centrifugal switch and wiring. Hooked up the spare cap and quickly turned it on then off. Started very fast and I think it stopped so fast the blade loosened and kept spinning. Unless it started up backwards...

I’ll see if I can pick up a couple new capacitors Monday or try my luck ordering online.

Thanks for the help.

Dan