svaurez
Member
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- California
Are there any advantages in having a neutral that is switched vs. a neutral that is not.It seems like a lot of extra work to create a seperately derived system.Is there a good reason for this?
Generator/Transfer switch
- Thread starter svaurez
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ron
Senior Member
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Re: Generator/Transfer switch
If you go with the switched neutral, you can leave the neutral and frame bonded (as it comes from most factories).
If you go with the switched neutral, you can leave the neutral and frame bonded (as it comes from most factories).
brian john
Senior Member
- Location
- Leesburg, VA
Re: Generator/Transfer switch
Based upon my experience a four pole is best way to go. The reason being; most electrician DO NOT install a three pole ATS and associated generator properly. The neutral is left as shipped from the factory bonded to the generator frame.
And what extra work?
Based upon my experience a four pole is best way to go. The reason being; most electrician DO NOT install a three pole ATS and associated generator properly. The neutral is left as shipped from the factory bonded to the generator frame.
And what extra work?
Ed MacLaren
Senior Member
Re: Generator/Transfer switch
Bennie,
I think this is the one you are referring to.
Disclaimer - The following sketch is offered to illustrate basic principles only, and is not intended to represent any actual installation.
Ed
Bennie,
I think this is the one you are referring to.
Disclaimer - The following sketch is offered to illustrate basic principles only, and is not intended to represent any actual installation.
Ed
Re: Generator/Transfer switch
Bennie, if you can get your hands on the IEEE Orange Book, look in chapter 7 at the vaious problem configurations of the generators with GFP relays. The problems can be found on both non SDS and SDS.
Good drawing Ed, what's with the disclaimer? :roll:
Bennie, if you can get your hands on the IEEE Orange Book, look in chapter 7 at the vaious problem configurations of the generators with GFP relays. The problems can be found on both non SDS and SDS.
Good drawing Ed, what's with the disclaimer? :roll:
Re: Generator/Transfer switch
If you were to have a site that required two ATS with GFP you can trip the main while on normal supply with no fault what so ever.
[ October 08, 2003, 10:24 PM: Message edited by: dereckbc ]
Yes, look at Ed's drawing. The fault has to go back to the N-G bond at the service to return to the generator neutral, which will cuase unbalanced current flow through the service GFP causing a false trip.
If you were to have a site that required two ATS with GFP you can trip the main while on normal supply with no fault what so ever.
[ October 08, 2003, 10:24 PM: Message edited by: dereckbc ]
Ed MacLaren
Senior Member
Re: Generator/Transfer switch
The following sketch is offered to illustrate basic principles only, and is not intended to represent any actual installation.
Ed
Yes.
The following sketch is offered to illustrate basic principles only, and is not intended to represent any actual installation.
Ed
Re: Generator/Transfer switch
Has anyone calculated the odds of a fault developing while the one feeder is on generator power, when the rest of the load is on utility power?
I think the lottery has better odds.
Usually when the generator is operating, the main system is dead, there would not be any power to dump the breaker.
Neutrals were required to be switched on generator supplied separately derived systems in the 1930's, when they were known as "AC systems without external connections" This was a long time before GFI's were introduced or required.
[ October 09, 2003, 12:01 PM: Message edited by: bennie ]
Has anyone calculated the odds of a fault developing while the one feeder is on generator power, when the rest of the load is on utility power?
I think the lottery has better odds.
Usually when the generator is operating, the main system is dead, there would not be any power to dump the breaker.
Neutrals were required to be switched on generator supplied separately derived systems in the 1930's, when they were known as "AC systems without external connections" This was a long time before GFI's were introduced or required.
[ October 09, 2003, 12:01 PM: Message edited by: bennie ]
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