I guess the question is whether LO V ESR testing is sufficient for capacitors used in HI V service? Are there any advantages to using a HI Voltage leakage tester over using a LO V ESR tester?

 

But isn't the ESR a completely different "parameter" than leaking?

 

Parameter, yes, but still an indication of DC voltage across the capacitor as leakage? I'm seeing both 600 -1000V leakage testers and then those that use lower voltages to test high voltage capacitors for leakage... I have a bunch of old tube gear and high voltage power supplies that I need to work on and would like to check their capacitors rather than just replace them all. I already know most will need to be replaced.

EDIT: Arghhh... ESR is for the AC component, not the DC! Sorry...

 

Check this out, @SamR

https://www.patreon.com/posts/another-released-17569473

 

Check this out, @SamR

I've seen that and considering a build. He has a few versions improving on it that follows.

 

Check this out, @SamR

https://www.patreon.com/posts/another-released-17569473

This might be helpful:

https://www.eevblog.com/forum/testg...r-tester-ultra-version/msg2913996/#msg2913996

 

Wait a minute! ESR is equivalent SERIES resistance, in other words it's a limit and loss dealing with the CURRENT THROUGH the capacitor, which is a pretty important parameter when you're using one of these as a critical capacitor used in a switching power supply, the ESR and the series resistance loss of the switching inductor are usually the two most important factors in determining the overall power conversion effficiency (the loss in the switch device and the schottky switching diode count too). In fact it's so important that it's sometimes specified as measured on a single capacitor at more than one frequency. It's a loss that occurs primarily while switching is occurring, whereas leakage is mostly important when the switching is stopped and you want to see how long the charge remains on the capacitor at a very light load. Pretty much apples and oranges!