generators, bonded neutrals, and transfer switches

Status
Not open for further replies.
Re: generators, bonded neutrals, and transfer switches

I believe that for the application jlp16au describes, Ed MacLaren's drawing is electrically correct.

I also believe that crossman's comments about perfectly legal, feasible, & desirable are on the money.

Is what we have here, simply another case where NEC is unclear. This may be partly because because NEC strives so hard to not be a training manual/instruction manual for untrained persons.
 
Re: generators, bonded neutrals, and transfer switches

don
Sorry I missed so much of the debate, since I was the first fish to bite. I didn't read the the post carefully, and didn't notice the reference to neutral and frame not being grounded. It would seem it doesn't meet the description of a portable generator in 250.34(A)
Jim T
 
Re: generators, bonded neutrals, and transfer switches

Ok, I would bet that the neutral IS bonded to the frame or else it could not be used in a stand alone method for the receptacles. Does the generator have receptacles on it?

Also, is you use the gen bonding jumper for your neutral, and break the neutral at the transfer switch, is the #12 bonding jumper on the back of that repceptacle gonna be enough? According to code shouldn't the gen have a #6 bonding jumper?

-Derek
 
Re: generators, bonded neutrals, and transfer switches

Dereck,
Ok, I would bet that the neutral IS bonded to the frame or else it could not be used in a stand alone method for the receptacles. Does the generator have receptacles on it?
Click to expand...
Look at the original post. It has a quoted statement from Honda that says the neutral is not bonded to the generator frame. Look at the wring diagram of this Honda Generator. The neutral is not connected to the frame.
Don

edited to add link

[ January 15, 2005, 04:36 PM: Message edited by: don_resqcapt19 ]
 
Re: generators, bonded neutrals, and transfer switches

I saw nowhere that it said it wasn't bonded... It said to prevent shock it should be GROUNDED... ie: ground rod... but never said anything about neutral. But if the neutral IS floating... Then how is this safe to use for 120v outlets? Without a bonding jumper?

Then it would be safe to remove it from ANY generator?

[ January 16, 2005, 01:39 AM: Message edited by: ddderek ]
 
Re: generators, bonded neutrals, and transfer switches

Dereck,
The wiring diagram in that Honda manual shows the neutral "floated". There is no electrical connection between the frame and the neutral. The frame is only connected to the grounding terminals on the receptacles. There is no bonding jumper.
Don
 
Re: generators, bonded neutrals, and transfer switches

Originally posted by don_resqcapt19:
Dereck,
The wiring diagram in that Honda manual shows the neutral "floated". There is no electrical connection between the frame and the neutral. The frame is only connected to the grounding terminals on the receptacles. There is no bonding jumper.
Don
Click to expand...
Don, if this is true, HOW can Honda's generators be used and safe for use as stand alone units for receptacle power? Without a bonding jumper?
 
Re: generators, bonded neutrals, and transfer switches

Could be they are counting on the on board GFCIs to protect the user.

Strictly speaking a portable generator used to power hand tools would be safer with no connection at all to earth. :p
 
Re: generators, bonded neutrals, and transfer switches

Originally posted by don_resqcapt19:
Dereck,
The wiring diagram in that Honda manual shows the neutral "floated". There is no electrical connection between the frame and the neutral. The frame is only connected to the grounding terminals on the receptacles. There is no bonding jumper.
Don
Click to expand...
http://www.hondapowerequipment.com/Gen_Own_Web/pages/pdf/31Z21600.pdf

The link above is to a Honda Gen Manual that shows and warns that it has floating neutral system. Now the other Honda had floating neutral but gfci protected outlets... maybe that was safer, but this one has Floating Neutral AND no gfci protection... If what everyone is saying is true, HOW IS THIS SAFE FOR USE??? (as a stand alone unit)
 
Re: generators, bonded neutrals, and transfer switches

I am going to agree with iwire's statement above about ungrounded portable generators. For power tools, it may very well be safer to leave them ungrounded.

Back in the day when electricity was first coming into use, there was huge debate about the safety of grounded systems versus ungrounded systems. Grounded won out, but that does not necessarily mean that grounded systems are safer. There are trade-offs in both systems. Both have their safety good points and their safety bad points.

The main factor that caused the original utility's to opt for grounding the secondaries feeding premises wiring was to limit the voltage in the building in the case of accidental contact with higher voltages as could occur in the case of a transformer insulation breakdown where the primary came into contact with the secondary. This was a common occurance with the insulation types that were available in the old days.

In the very back of the Soares grounding book, there are excerpts of discussions about the "grounded vs ungrounded" topic from back long ago. Very interesting.

Everyone always assumes that grounded is automtically safer than ungrounded, but it ain't necessarily so.
 
Re: generators, bonded neutrals, and transfer switches

Originally posted by crossman:
Everyone always assumes that grounded is automtically safer than ungrounded, but it ain't necessarily so.
Click to expand...
Crossarm they was a poster here named Bennie who was quite a character and very knowledgeable. :(

Anyway, he would tell us that by grounding we have brought half the circuit that will kill into the users hands.
 
Re: generators, bonded neutrals, and transfer switches

That is a very succinct way of putting it.

I am sorry that I arrived after Bennie's passing. I am certain I could have learned something from him.
 
Status
Not open for further replies.
Top