Main-breaker converted to transfer panel...

[LarryFine]

I remember ther being a rule about having two breakers feeding a panel, one from the utility and one from an optional stand-by generator, and a mechanical interlock between them.

There was mention of the mechanical inetrlock not being dependent on the cover of the panel being in place, meaning that this kind of interlock wouldn't be legal, yet they're declared to be UL and NEC compliant.

Here are a couple of the type to which I'm referring:

I scanned the NEC and can't find any reference to this now. Any comments welcome.

 

[iwire]

Re: Main-breaker converted to transfer panel...

IMO if they are listed for the use they are fine.

I think as far as as the NEC and the labs are concerned the cover is always on in the field.

Once a non-qualified person starts working with the tools no interlock is 'unbeatable'

 

[stud696981]

Re: Main-breaker converted to transfer panel...

Square D makes one of these for there 150 to 225amp panels. I have not installed one of these, but supposedly it allows you to back feed one of their panels and it switches the main breaker with the back feed breaker.

 

[steve66]

Re: Main-breaker converted to transfer panel...

Strange, once you take the cover off, the label that says "Do not operate without cover installed" is gone. I hope there is another label inside the box.


I would think the utility might have some say in what is acceptable for an generator interlock. It's their people who get hurt by backfeeding generators.

Steve

 

[LarryFine]

Re: Main-breaker converted to transfer panel...

Originally posted by steve66:
Strange, once you take the cover off, the label that says "Do not operate without cover installed" is gone.

I know what you mean. My clothes dryer has instructions on the inside of the door. Guess what #1 says...

"Insert clothes, close door."