[SOLVED] Choosing high voltage relay

[bosskardo]

I have a high voltage withstand tester and I'd like to use a relay to switch its path. That way I can do different tests without moving wires.
The problem is that the tests use as high as 2kV voltage. Allthough the current is low, max 10 mA. Tests run with AC nad 50 or 60Hz.
Test environment is indoors but the relay will get a lot of use.

I'm at a loss how to choose a relay, all high voltage relays are also high current but I don't need high current.
I don't know how big the safety factor should be. The tester monitors the voltage and current and cuts of if either goes over the limit but there is bound to be some delay. I think the safety factor can be a lot lower than motors(as I don't think I'll have problems with big transients) but how much. Relays are usually overdimensioned by a factor of 5 to 20. Could I use 5?
How much does hot switching damage a relay thats not meant for it? If I'm planning on avoiding it but there could be an event when it happens, should I still use a relay thats meant for hot switching? I'm tring to avoid sealed inert gas or vacum relays and thats why I'd like to use one with as low voltage as possible( if I'm not wrong then most relays from 5kV up are sealed).

How would I go abaout choosing a correct relay. I have read several guides but they weren't much help. Can someone help me?
Thanks

 

[jiripolivka]

I have a high voltage withstand tester and I'd like to use a relay to switch its path. That way I can do different tests without moving wires.
The problem is that the tests use as high as 2kV voltage. Allthough the current is low, max 10 mA. Tests run with AC nad 50 or 60Hz.
Test environment is indoors but the relay will get a lot of use.

I'm at a loss how to choose a relay, all high voltage relays are also high current but I don't need high current.
I don't know how big the safety factor should be. The tester monitors the voltage and current and cuts of if either goes over the limit but there is bound to be some delay. I think the safety factor can be a lot lower than motors(as I don't think I'll have problems with big transients) but how much. Relays are usually overdimensioned by a factor of 5 to 20. Could I use 5?
How much does hot switching damage a relay thats not meant for it? If I'm planning on avoiding it but there could be an event when it happens, should I still use a relay thats meant for hot switching? I'm tring to avoid sealed inert gas or vacum relays and thats why I'd like to use one with as low voltage as possible( if I'm not wrong then most relays from 5kV up are sealed).

How would I go abaout choosing a correct relay. I have read several guides but they weren't much help. Can someone help me?
Thanks

HV relays exist but I think it is difficult to find an available commercial model at a reasonable cost. I would suggest to modify an existing relay. Attach glass-laminate extensions to the contacts so the gap is wider than 3-5 mm for 2 kV. Extension strips can be 1-2 cm long. Soak finished laminate strips before mounting in hot paraffine wax to prevent water condensation. Contacts can be simple aluminum or brass rivets, no silver is needed at > 500 V

If the corona is a problem, use a blower (or a vacuum cleaner extension)to blow dry air over the gap. Enclose the device if possible to prevent water condensation in a plastic box, and use well insulated wires for connections.
This was my handling 5 kV when I needed it, and it worked well.

 

[kam1787]

**broken link removed**[backId]=2872

https://www.te.com/catalog/feat/en/c/20439?BML=10576,16354,16453

 

[bosskardo]

**broken link removed**[backId]=2872

https://www.te.com/catalog/feat/en/c/20439?BML=10576,16354,16453

Thanks but these are too expensive.
I found some reed relays on farnell that should work