Motor blowing capacitor

[DZL JIM]

I posted this in the general section before I realized I should of just posted here.
I just got a 20 yr old Forward lift (new to me) installed and tried to power up.
It promptly blew the capacitor.
I got a new capacitor from McMaster Carr and it blew that one.
It's 2 hp 220v motor. Pretty simple to hook up, 2 wires and ground.
No wires on motor are grounding, per Ohmeter tests.

Any thoughts what could cause the motor to blow capacitors? Just a bad motor?

Motor rebuilder's only advice is to bring it in with $100 for him to look at and tell me what he finds. I'd like to save that for last resort.

Thanks for any help.

 

[SGKent]

I am not a motor guy but understand electronics. Recently had to ask motor questions so someone will be along who knows much more than me. I am guessing this is a single phase motor and not a 3 phase? Somehow either thru wiring or faults you are getting either 120 or 240 directly across that cap and it is acting like a direct short. Another possibility is that the prior owner replaced the caps with under rated ones and you duplicated his issue. What I would do - on the motor there should be a wiring diagram. Make sure the wires are all in the correct place for your configuration. Some motors are dual 120/240.

 

[DZL JIM]

The original capacitor was very old and discolored, looked to me like it was there for a while. It's always possible it was replaced, but it sure looks original to the lift.

Yes, it's single phase, and I was told it's only 220 v. For kicks I wired it up as 110v and toasted another capacitor, so I'm pretty sure it's only a 220 v motor as I was told.

There is no wiring diagram on the motor.

Thanks for the tips.

 

[nehog]

Check the centrifugal switch and make sure you reinstalled it correctly after checking/cleaning the contacts. They are easy to get in wrong, with the contact on the wrong side of the switch.