# bond & floating neutral generators and transfer panels



## Nevin (Dec 6, 2020)

I have bonded neutral portable generator with full GFCI protection connected to a manual transfer panel in the house which also transfers the neutral. All works ok with the exception of the well. Haven't tried the sump pump. My question is this, can I connect a floating neutral portable generator to my transfer panel whichout any issues? Must I ground the portable generator outside if it is a floating neutral generator? Hopefully, I don't need to change anything in the manual transfer switch. I think the problem with existing setup it that the well being 500 ft deep loses sufficient current over the distance to trip the GFCI breaker. Thanks


----------



## iowagold (Jan 22, 2020)

you want an un-bonded gen setup to work with a transfer or interlock setup.
it will get the ground from the breaker panels systems ground stake.

what make and model of generator do you have?
we can look at the wiring diagram.

if you have a proper cord from the un-bonded generator to the transfer panel you are all set.

a bonded generator is a construction generator. but they can be modified for use on a back up power system.
depending on the make and model there is a jumper from the case to the generator neutral that can be removed.
make sure to mark the generator as un-bonded.with a large sticker!

if it is to be used as a standalone generator or construction style it will need a ground stake at the generator to the ground point on the generator frame.


----------



## Nevin (Dec 6, 2020)

iowagold said:


> you want an un-bonded gen setup to work with a transfer or interlock setup.
> it will get the ground from the breaker panels systems ground stake.
> 
> what make and model of generator do you have?
> ...


Thanks Paul for your reply.
The generator is a Generac XP8000e. The cord is 4 leads, two hots, a common, and ground. I have the directions, I think they are from Generac, to disconnect the bonded lead(s). It requires getting into the generator head. Not as simply as I understand a Honda is. It appears that it would be difficult to add a switch that could be flipped to chose depending on use. If there were a kit to do that it may be the cat's meow. The Reliance transfer panel has 3 breakers when source is changed; the third one for the common. Regarding my original question, will an unbonded generator work with my present transfer panel wired the way it is? I realize that if another generator has only a 220v outlet with 3 leads, instead of 4 like my Generac, I would need an adapter; one that would combine the common and ground in the adapter.

Although the XP8000e was somewhat pricey, I considered it worth it because of the voltage regulating and THD's (Total Harmonic Distortions). BOTH are important if powering digital type appliances such as microwaves and refrigerators that have digital componets, or computers.


----------



## motormonkey (Jul 10, 2016)

Whoa! Make sure that your transfer switch does indeed switch neutral along with the two hot legs. That is not commonly done in a residential installation.

If your transfer switch swiches the neutral in addition to the live leads, then your generator is a _separately derived system_. When the transfer switch is in the generator position, the bond between neutral and ground in your electrical box is removed from the circuit. This bond should then come from the generator. If you do have a full three-wire transfer switch, you need to leave the neutral/ground bond in the genny intact.

What model of Reliance transfer switch do you have?


----------



## Nevin (Dec 6, 2020)

[/QUOTE]
Thanks motormonkey for your reply
I agree with you that having a bonded neutral generator is a separately derived system. That is why I have the transfer panel that I have. The model of the Reliance transfer panel is Cat No XRC1006C. It is described on the tag as a 3 pole main linkage transfer panel. I think the generator and the transfer panel are the correct match. My question is this. If I have a floating neutral generator do I have to do anything more than ground the generator to say a grounding rod? Would I additionally have to make a change in the transfer panel?

My understanding is that with my present system the generator is already grounded to the panel ground.


----------



## iowagold (Jan 22, 2020)

Nevin said:


> Thanks Paul for your reply.
> The generator is a Generac XP8000e. The cord is 4 leads, two hots, a common, and ground. I have the directions, I think they are from Generac, to disconnect the bonded lead(s). It requires getting into the generator head. Not as simply as I understand a Honda is. It appears that it would be difficult to add a switch that could be flipped to chose depending on use. If there were a kit to do that it may be the cat's meow. The Reliance transfer panel has 3 breakers when source is changed; the third one for the common. Regarding my original question, will an unbonded generator work with my present transfer panel wired the way it is? I realize that if another generator has only a 220v outlet with 3 leads, instead of 4 like my Generac, I would need an adapter; one that would combine the common and ground in the adapter.
> 
> Although the XP8000e was somewhat pricey, I considered it worth it because of the voltage regulating and THD's (Total Harmonic Distortions). BOTH are important if powering digital type appliances such as microwaves and refrigerators that have digital componets, or computers.


please post the exact model number on the transfer panel so i can look at the instructions and maybe find a oem wiring instructions for that kit.

I shy away from using any switch at any rating to cut in and out a neutral bond.
it just is not safe period.
they want it to be the hardest connection in a gen... good for over 50 amps on most smaller 3.5 kw gens... and up to 100 amps on larger 7 kw gens.
that way if something goes wrong inside of the gen set to the chassis or the head case it should pop a breaker before some one gets hurt.

the proper way to do these construction gens on a house or shop setup is to use a proper un bonded gen and a 4 wire plug and cord to the interlock or transfer switch.
the ground is made at the main breaker panel using the house ground stake array.

and that brings up the house or shop grounding.
make sure it is updated and has real good connections.
turn off the main before screw or wrench checking those connections. just to be safe!
use some anti oxide grease on the outdoor cable to ground stake connections..
that will hold back the corrosion on the copper that is exposed to earth splatter with rain and snow.

stay safe out there!


----------



## motormonkey (Jul 10, 2016)

In answer to your question, in a separately derived system, the neutral conductor of that separately derived system (the generator) should be bonded to ground, just as your existing utility supply is inside the breaker panel. Your understanding is correct that your generator and transfer switch are already connected to your existing ground system and will be fine that way. Separately derived systems have separate independent hot legs and neutral from other systems such as your utility connection, but they can still share a common ground system.


----------



## Nevin (Dec 6, 2020)

iowagold said:


> please post the exact model number on the transfer panel so i can look at the instructions and maybe find a oem wiring instructions for that kit.
> 
> I shy away from using any switch at any rating to cut in and out a neutral bond.
> it just is not safe period.
> ...


I created a webpage with some pictures and explanation. Hope it helps questions will still have to be answer on this site below. Click on the link called Transfer Panel.  Transfer Panel
Question again:
1. Is there anything that I need to change or alter in the above transfer panel *if I used a floating neutral generator*? 

I think that all I have to make sure is that the neutral and the ground are connected together either in the generator, or in case of a three prong 220 volt outlet on the generator, I would need to make sure that the adapter plug between the generator's three prongs and the four wires to the panel connect the neutral and ground together. Also, I think the generator frame should be attached to a grounding rod or some kind of ground.


----------



## iowagold (Jan 22, 2020)

*click here for the reliance XRC1006C page*
this is the op sub gen panel.

looks like it will work at least at first glance.
not my choice for a gen sub panel and switch.

as long as the generator is a floating ground gen with a 4 wire cord.
it should work ok.

be sure to check with local code.
some of the after market mfg gear may not pass local codes in some areas.

looks like reliance did a custom hybrid panel with some 3 phase parts.
and some custom linkage for the neutral switching.
switching the neutral could be a future issue... not my choice of a way to do it.

i prefer square d QO series load center and an interlock for the main to the gen inlet breaker
it works for our local code as well as iec 2020 code.

4 wire in from the floating ground gens.
easy to switch over.
and off the shelf parts for repairs.


----------

