Capacitor blew up!

[Marc]

The other day i had the band saw running to make some adjustments and i started to smell something. I looked under the base (old grizzly 16") and a small puddle was forming. The capacitor was dripping.
Today i installed a new capacitor and when i turned it on it gained speed but with a loud hum. After about 30 seconds the capacitor popped like a firecracker and made a bunch of smoke.
Any clues?
Again this is another flood saved tool from 2012 motor was taken apart, cleaned and bearings changed

[EricU]

are you sure you put it in right way 'round?  I've only managed to pop caps when I installed them backwards.

[Marc]

I dont see any markings by the connectors,,my son said the light's flickered. The new one has the white label

[Robert Adams]

Make sure the centrifugal switch is working.

[Marc]

I guess i have to open this thing up again....ugh

[TDKPE]

Make sure the centrifugal switch is working.

My first thought, too.  If the switch doesn't open, the capacitor won't be cut out, and it's not intended for continuous use, nor is the start winding.

[Marc]

Yes...that seems to be what it is. Earlier i found a set screw on the floor by the bandsaw and didn't know where it came from. As i was taking the motor fan cover off the back of the motor i touched the centrifugal switch and noticed it spun on the shaft. Thats where the set screw fell out of. I put a little adhesive on the threads and put it back but i dont have another capacitor to test it out.

[Joe K1]

Be sure to note when the switch opens on starting and also closes on run down.  Cycle power on for a couple of seconds then off to note this.  As mentioned, don't wait for smoke or a pop as an indicator.  On newer motors (imports) the setscrew is sometimes used to position the centrifugal assembly lengthwise on the shaft to obtain the cut-in / cut-out speed.  Older motors tended to have an adjusting screw on the electrical switch for this adjustment.

Joe

[Marc]

There was a shallow hole in the shaft where the set screw sat so i put it back in that spot. I hooked up the blown capacitor just to see and it started fine. I still have to order one.

[mike4244]

Marc, you may be able to buy a capacitor locally. Do a search with your zip code for electric motor repair. I bought capacitors at a electric pump  supply house. I found that American made capacitors are half the size of Chinese ones.
At first I thought I had the wrong ones til I read the info on the old compared to the new ones. The electrical info was the same so I hooked the capacitors up. I replaced both a run and start capacitors on a metal lathe. Been working perfect for the last 4 years.
mike