Electrical Relay Question

[Curt Harms]

Hi All

On Grainger's web site, I see definite purpose contactors rated 240 volts with one leg switched and one leg straight through. Is it OK to leave one leg hot on motors? I know the motor wouldn't run with one leg open but it seems smarter to open BOTH legs.

Not an electrician, don't play one on TV and didn't even stay at a Holliday Inn Express, but I'm curious.

Curt Harms

[Ken Garlock]

It is OK to leave one leg hot from an electrical perspective, but I would have "warm & fuzzy" feeling if both legs were switched. Personally, I would look for a double pole relay. The important thing to look for is the amperage rating of the contacts. The voltage rating is an indicator of relay insulation. I would go with a contact rating that is at least 50% more than the full load current rating of the motor you are using.

[Curt Harms]

Thanks Ken

Curt