[Amps] More power supply

[Barrie Smith]

I've been testing and measuring this and that on my "growling" power supply, in an effort to eliminate all possibilities before I dig in and change the diodes.

One thing that I noticed that has me puzzled is, as I crank-up the voltage with the variac, a small arc from one of the oil capacitor cases to a very nearby ground.

This happens just on about a 500 volt crank-up, and only once.

I've been using oil caps for years and have never deliberately grounded the case, nor have I ever seen advise to do so.

I removed that cap and noticed no difference in the growl.

I also measured the capacitance and it was 32 mfd, as stated on the case.  It also has about 3 mfd from each terminal to the case.

Should oil capacitor cases be grounded?

TNX & 73, Barrie, W7ALW