ECN Forum Forums General Topics of the Trade Non-US Electrical Systems & Trades AC insulation resistance tester

Have any of you guys used an ac insulation resistance tester?

Yes lyle,
I use one every once in a while here.
I take it that you are talking about a Hi-Pot test (or Dielectric Withstand Test), as opposed to the plain-vanilla DC Insulation Resistance test?.

Yes Trumpy, thanks for the reply.
I know that they are required for dielectric testing of certain products and electrical systems. An output of 3750vac even though current limited is not appropriate in the wrong hands.
What I wanted to know was if these instruments had a place in the field rather than in the production line lab.

Way back in the last century, (ok 12 years ago) I had to use such a beast as part of the portable appliance testing regime where I worked. Output as you say, up to 3750 volts AC, current limited to 5/10/15 mA, selected by a switch, with a deeply recessed "operate" button so it couldn't be energized accidentally. I agree they should only be used by competent persons trained in the dangers of high voltage.
With a probe carrying that kind of voltage, you could do a lot of damage to some kinds of electronic devices. But it helped pick up deteriorating insulation on double insulated tools and appliances, so yes, I believe they do have a place in the field, just a very narrowly defined one.

Lyle,
We have a 20kV model here at the PoCo, it's used for flash testing HV cables, transformers and switch-gear, as well as the odd suspect bushing insulator.
I agree fully with yourself and Chipmunk, 3.75kV is not the sort of cat you want to let out of the bag, these voltages are lethal with the most minute of current levels.