[jeffrey001]

A common problem with Electrolytic caps as they age, they lose capacity.
There is a large bank typically wired on the output of the 3ph bridge.
May need replacing, Seen it a few times.

Yes, I know about the capacitor, I always wanted to buy a spare one, now it's the time. Maybe two

I don't understand why a 20 amp breaker could cause problem. If the lathe could draw more than 20 amp on a 240 volts, the breaker would just shut off. I could replace it with a 30, 40 or 50 amp breaker and it would not make any difference..

Thanks a lot for all the replies

[mactec54]

Yes, I know about the capacitor, I always wanted to buy a spare one, now it's the time. Maybe two

I don't understand why a 20 amp breaker could cause problem. If the lathe could draw more than 20 amp on a 240 volts, the breaker would just shut off. I could replace it with a 30, 40 or 50 amp breaker and it would not make any difference..

Thanks a lot for all the replies

You did not answer the question, what the spindle motor Hp is this will tell you if your circuit is sized correct, Ok just checked Tormach and they have your machine using a 230v / 20A Breaker for the primary and a 120v 20A for the secondary

The VFD Drive does not just have a capacitor, it will have a bank of 6 to 8 large capacitor in the Bus, it is not a simple job to just rebuild the Bus, it is easy to check the Bus voltage though which you can do with a regular meter, this will tell you if you have a problem with it or not

How old is the machine???

No, the Breaker will only trip, if there is a short circuit it's there to protect the circuit, most will not trip from being undersized, that is not the purpose of a Breaker it is there and will trip if you have a short circuit or a major problem with the wiring

You can only size a breaker to the circuit cable wire size being used x 125% to 150% larger this is the electrical code requirement