305-6(a), Exception No.1. What is the reasoning for this exception? I know it's been in there for years. How can you tell if you meet this exception? I know the obvious if its over 5 kw but say you got a 4500 watt generator (which are common), how do you know if you meet this? I was told one way if you have dual voltage 120/240 then you would not meet that exception. Is that dual voltage reasoning (if true at all) because if you had 240, you would have 2 hot wires and one neutral thus equal 3 wires?
[This message has been edited by Joe Tedesco (edited 09-10-2001).]
Joe, Even if it is only a 2 wire generator, you can't use the exception. 250-20(b) requires the system to be a grounded system. There is nothing in 305 that says it doesn't have to be a grounded system and if it is grounded, then GFCI protection is required. If its not grounded, it is a violation of 250-20(b). Don(resqcapt19)
I posted the question to the board and don't really agree with the responses and here's why. I don't think the generator has to be grounded and if it was, then what requires GFCI protection? That is what the exception is all about, not requiring GFCI's. What I basically want to figure out is how is an inspector supposed to know if a generator meets that exception? Thanks
Re: Temporary Generator#78341 09/12/0109:03 AM09/12/0109:03 AM
Buddy, In my opinion, this exception could be used if you verify that there is not a bond between the frame of the generator and a circuit conductor. The exception also requires that it only be a 2 wire generator, which would preclude the use of a 120/240 volt generator. Are there any portable generators currently available that do not have a conductor bonded to the frame? I've never seen one without this bond.
Is a portable generator a separately derived system?