Another Generator Grounding Question

[goldstar]

I received some more info on this topic from PGMA.

UL?s 2010 version of the White Book reflects what is written in UL standards, which includes UL 2201 (Portable Engine-Generator Assemblies). UL 2201 requires that portable generators must bond the neutral conductors to the generator frame.

The problem is that UL 2201 is a "private" standard and NOT a national (ANSI) standard. Since UL 2201 was published in 2009, I am not aware of ANY manufacturers that have listed products to UL 2201.

There is no ANSI standard that requires a bonded-neutral generator. Therefore, installing a "floating neutral" portable generator as a non-separately derived system, using a two-pole transfer switch, is perfectly acceptable.

I asked the following questions and received these answers (in blue)

1. Since there is no ANSI standard requiring manufacturers to fabricate portable units with neutral-to-frame bonding why do they come shipped as such ? Is the assumption that they are going to be used in the field and not connected to premise wiring ?
   
   Not all portable generators are bonded neutral. In the U.S., approximately half of all portable generators sold are bonded neutral and half are floating neutral
   
   
2. Is there any danger in using the portable with the neutral-to-frame bonding in place when connected to premise wiring ?
   
   For portable generators with a bonded neutral, I think you have to either remove the bond or connect it as a separately derived system (3 pole transfer switch) in order to comply with NEC.
   
   
3. Is it acceptable and would there be any danger in disconnecting that bond when connected to residential premise wiring ? Any of the units I've used have no instructions to break that bond when used this way.
   
   You would have to contact the manufacturer for an answer to that question
   
   
4. Are the manufacturers required to provide a simple means to disconnect that bond when used in this way ?
   
   Not that I am aware of.
   

I'll keep hunting for more info on this. :thumbsup:

 

[qcroanoke]

I received some more info on this topic from PGMA.

UL?s 2010 version of the White Book reflects what is written in UL standards, which includes UL 2201 (Portable Engine-Generator Assemblies). UL 2201 requires that portable generators must bond the neutral conductors to the generator frame.

The problem is that UL 2201 is a "private" standard and NOT a national (ANSI) standard. Since UL 2201 was published in 2009, I am not aware of ANY manufacturers that have listed products to UL 2201.

There is no ANSI standard that requires a bonded-neutral generator. Therefore, installing a "floating neutral" portable generator as a non-separately derived system, using a two-pole transfer switch, is perfectly acceptable.

I asked the following questions and received these answers (in blue)

1. Since there is no ANSI standard requiring manufacturers to fabricate portable units with neutral-to-frame bonding why do they come shipped as such ? Is the assumption that they are going to be used in the field and not connected to premise wiring ?
   
   Not all portable generators are bonded neutral. In the U.S., approximately half of all portable generators sold are bonded neutral and half are floating neutral
   
   
2. Is there any danger in using the portable with the neutral-to-frame bonding in place when connected to premise wiring ?
   
   For portable generators with a bonded neutral, I think you have to either remove the bond or connect it as a separately derived system (3 pole transfer switch) in order to comply with NEC.
   
   
3. Is it acceptable and would there be any danger in disconnecting that bond when connected to residential premise wiring ? Any of the units I've used have no instructions to break that bond when used this way.
   
   You would have to contact the manufacturer for an answer to that question
   
   
4. Are the manufacturers required to provide a simple means to disconnect that bond when used in this way ?
   
   Not that I am aware of.
   

I'll keep hunting for more info on this. :thumbsup:

Not a direct answer in there. :lol:
But I wouldn't expect one either.
They don't want to hear "but the people at PGMA said........

 

[goldstar]

Not a direct answer in there. :lol:
But I wouldn't expect one either.
They don't want to hear "but the people at PGMA said........

You're probably right but I will continue to do more research on this. I just want to make sure that we all use portables safely and that none of us mis-connects a unit and causes damage, injury or death. Logically speaking, I believe connecting a portable in accordance with UL-FTCN is the absolute safest way to go. Realistically speaking, unless the NEC specifically insists that portables be connected this way I don't see the PG industry changing any time soon.

 

[iceworm]

Why would mfgs not install a switch where you could select bonded neutral, or floating neutral(or bonded, non-bonded)l. Where you could select what you needed? Does not seem like it would be hard to do.

Don't know. Just a guess: Why spend money to install a control that most of their clientele will not know how to operate.

Personal opinion: A portable gen with on-board receptacles should come with and N-G bond installed. It should also come with directions on how to remove the bond if the use requires non-sds.

ice

 

[iceworm]

Gold - Good Job:thumbsup::thumbsup:
Their answers looked fine to me - about what I would have expected.

ice

 

[goldstar]

Gold - Good Job:thumbsup::thumbsup:
Their answers looked fine to me - about what I would have expected.

ice

Thanks. At least we're getting down to some of the reasons why units are bonded or not as well as the reason for their design characteristics.

 

[qcroanoke]

Personal opinion: A portable gen with on-board receptacles should come with and N-G bond installed. It should also come with directions on how to remove the bond if the use requires non-sds.

ice

I agree. At least we would know we could do it without violating the UL listing. Oh wait..... Most of them aren't listed.....