Electure,

The problem isn't that the contactor would inadvertantly close by itself without control power, but it is fairly common to see one or more of the contacts weld themselves closed during operation.

I think this is a really BAD idea. Yeah you're right, anyone working on this spa should lock out the breaker and check for voltage before doing the work, but unfortunately we live in the real world, we have to plan for the idiot that doesn't take the time.

There has to be an OSHA or some other rule prohibiting this somewhere, I can't imagine this being an acceptable means of meeting the requirements of 680-12. I know that breaking control voltage is not an acceptable means to lock out equipment at the manufacturing plant that I work at, and management would never have a rule like that unless some law forced them to.

I say put the disco in according to 680-12, and tell the guy with the money to have someone paint some flowerdy stuff on it [Linked Image]

Matt