Trouble with Rotary Phase Converter

Hello all, using the lathe yesterday running off the RPC, when a funny noise came from the converter, best described as a muffled fart (sorry). Lathe still running OK, but thought I'd better have a look inside it. Slight burning smell, with one of the capacitors different to the rest. Its a Boost Energy made converter, bought second hand and probably seen a lot of use.

Questions, does it look like the capacitor is toast, and is this common with the age of the unit ?. Also, would some other fault have caused this to happen, or will I get away with a new capacitor if it is indeed u/s ?.Thanks in anticipation, and a happy and healthy new year to all.

Looks like the capacitor at rear left has popped, is that brown ring a seal?

Hello Kwil, yes, thats the odd one out. Whether that brown ring is normal or faulty, Ive no idea !. Its certainly different to the rest.

I may be telling you to suck eggs, but be careful when you start unplugging capacitors etc, they may still be charged up even though everything is turned off.

I agree with Kwil, it seem that you have capacitor which has gone short circuit. Disconnect the entire device from the main electricity. I could not see any external capacitor discharge resistors, but they could be internally mount within the plastic tube. Anyway I suggest you leave the device for an hour then using an insulated handled screw driver short out ALL the terminals on each capacitor., one to another. Don't be alarmed if it gives a cracking sound. As the capacitor is taped to another one, remove the tape separate the pair, and on its case, hopefully, you should see its working voltage and capacitance value. These capacitors are MOTOR RUN type which are continuously rated. You will be able to buy a replacement from a local motor rewind shop, RS component or Farnell. have them, and they aren't charging postage either or weren't a month ago. Make sure that it has a working voltage of 440 volt or better, and that it is continuously rated (not motor stating). Often the exact capacitance value is not precise as they have a tolerance of + - 20%. I think you can change the capacitor your self, ensure that you buy like for like and then you have no problem with the LUCAR type connectors and the short link wires. John

Speedy and John, thanks for the advice.

John, I might need to pick your brains if I get stuck ! Many thanks all.