# The Grounding Question... Again



## Bluwolf (Nov 8, 2020)

I have tried to understand the whole grounding and neutral thing. When to, and when not to. But I always seem to get lost because of some detail or details in the thread I'm reading. So I'm going to ask for what to do in my specific situation. Please, not all the science behind it. Just what should I do in my situation. Actually, two situations, sorry about that.

Because I've talked my boss into setting up virtually the same situation at work that I have at home. We get more power outages at work than I do at home, why, I don't know. But the problem is compounded at work because we have 4 computers and a server to deal with.

My setup at home. Champion model 100296 dual fuel. I have an interlock. The 220 breaker is running to an inlet box on the other side of the wall. It's an L14-30 plug setup to the generator. This is what it says in my owner's manual:

"The generator system ground connects the frame to the ground terminals on the power panel. The system ground is connected to the AC neutral wire."

This is a video about converting to floating neutral for open frame generators like mine. Does this apply to me?





Work scenario. We have the same basic setup at work. Interlock, L14-30 inlet box. We tried using an older but decent Yamaha generator. It powered lights, etc, but the computers and server are all running through battery backups. We could get the computers up but the server stayed on battery back and wouldn't come on line or give us internet or phone. In short nothing really worked.

We decided to get another generator. This is why it should be basically the same scenario as me for the grounding/neutral situation. He bought a Champion 100231 dual fuel generator. So it's got the same AVR and ground/neutral blurb in the manual.

We were going to try and see if the Champion generator would work with the battery backups. If that didn't work, then were going bypass all the battery backups and use surge suppressor power strips that he has already bought.

Also, I thought I read somewhere that the whole ground/ neutral thing might be messing with the battery backups.

Is there an answer here that even a moron can understand?

Thanks, Mike


----------



## iowagold (Jan 22, 2020)

lol!
"salt of the earth"
mel brooks said that best.
history of the world part one.
yea you have to see that movie again!

ok on to the question.
if you are not running a ups or one ups per computer you are asking for trouble.
as well as cover the modem's and any switches power.
apc makes good units 
click here for the apc site for good info
a ups will buy you time to save your work and shut down safe.
the better units have parachute software that will auto shut down when the power fails after a set given time selected
just in case you are not there when the power fails to get the back up power generator in place.

and fiber in the home or biz networks rocks to eliminate and isolate any power issues.
and is faster for in house connection.
good for long connection runs over 100 feet.

basic you want depend on the existing breaker panel earth ground for the system earth ground.
make sure it is in good working order and up to date with the latest wiring code.
the generator frame will get the gen earth ground from the green wire in your 8-4 black is L1 red is L2 white is neutral green is earth ground (that is 8 gauge wire with 4 conductors or larger power cable) from the gen set to the house or shop inlet.

so make sure the construction generator is set up to be a back up generator by un bonding the frame or green chassis ground from the generators white neutral.
and make sure to label the generator for back up power use only.

with out getting all pointy head I think this is as simple as you are going to get.
GRIN!

and yes power back up for biz use is just a smart investment!


----------



## motormonkey (Jul 10, 2016)

"...Is there an answer here that even a moron can understand?..."
Yes, there is. (Not implying that you are a moron.)

The key point is: Regardless of what power system is powering your building, whether it is the utility or the generator, the neutral conductor and the grounding conductor from that system must be bonded (connected together) *at one and only one single point*.

If you have a transfer switch which only switches the two line conductors between utility and generator to the load, the utility and the generator share a common neutral conductor. (the neutral conductor is not switched) In this case, the bonding point between the neutral conductor and the grounding conductor in the utility breaker box or meter box can serve both systems, regardless of the position of the transfer switch. In this case, the neutral conductor in the generator should not be directly bonded to the grounding conductor.

If you have a transfer switch which switches the neutral conductor, in addition to the two line conductors, between utility and generator to the load, the utility power and the generator each have a separate and independent neutral. (the neutral conductor is switched.) In this case, when the transfer switch in in the utility position, the bonding point between the neutral conductor and grounding conductor must occur in the utility breaker box or meter box. When the transfer switch in in the generator position, the bonding point between the neutral conductor and grounding conductor must occur in the generator. In this case, the neutral conductor in the generator should be directly bonded to the grounding conductor.


I gather that you have uninterruptible power supplies whose sole task is to power the computers and server only long enough for the generator to come online. This works well when commercial grade equipment is used, but consumer grade Uninterruptible Power Supplies and generators are hit-and-miss for this task.


----------



## Bluwolf (Nov 8, 2020)

There is no transfer switch involved. This is where I get confused. It sounds like there are different kinds of transfer switches and depending on which you have dictates whether to do this step or not. But there is no transfer switch. There is just the circuit breaker for the generator, and the interlock. So I should do what it says in the video, disconnect the one wire, and make it a floating neutral, correct?

And as far as the battery back ups, is this extra ground causing the battery back ups not to function as they normally do when they're being used with regular utility power?


----------



## motormonkey (Jul 10, 2016)

Sorry about missing the part about the interlock. If there is simply a circuit breaker and an interlock, you are only switching the two line conductors and not the neutral, so you have a single common neutral. In that case, the neutral conductor in the generator should *not* be bonded to the grounding conductor. You should remove the ground/neutral bond in the generator.

This could possibly solve your problem with the UPS, but the likely explanation is that the generator is producing some sort of distortion on the output power, such as being off frequency or voltage, or producing harmonics, electrical noise, etc., and the UPS is detecting these input power defects, and is rejecting the input power. A generator service tech should be able to diagnose and correct most of these types of problems. Sometimes a UPS is simply too sensitive to minor power deviations, causing the same problem. This can sometimes be adjusted on the better commercial type UPS's.

If the output of the generator can't be adequately cleaned up by adjustments and repair, a power line conditioner on its output could help. Beyond that, you'll likely have to find a higher quality generator with a cleaner output.


----------



## Old man here (Nov 5, 2020)

What brand and model UPS are you using? I will post the instructions for the two I own.
They may match your UPS.
Setting them to the least sensitive settings allows them to stay on line with my Generac GP15000E.


----------



## iowagold (Jan 22, 2020)

5 stars for MM!
good answer!


----------



## Bluwolf (Nov 8, 2020)

Thank you motor monkey. That's exactly what I was looking for. I think the older generator was not helping matters. I'm hoping that the new generator with the AVR will make things a bit better. Plus fixing the bonded neutral will hopefully help.

And thank you, old man here. That first UPS, the APC looks very similar to the ones we have at work, they are APCs. We did not realize they had a sensitivity setting. Hopefully the combination of all these things will help us get where we want to be.

The new generator should arrive shortly. As soon as we can, we will try all this. I will let you all know how it goes.

Thanks again, Mike


----------



## Old man here (Nov 5, 2020)

Great, let us know how it works out.


----------



## ToolLover (Jan 13, 2020)

I quote MotorMonkey: "The key point is: Regardless of what power system is powering your building, whether it is the utility or the generator, the neutral conductor and the grounding conductor from that system must be bonded (connected together) *at one and only one single point*. "
I guess this is where the code and I disagree with you sir:
In today's NEC the neutral is isolated from the chassis or cabinet.
If you Ohm out the neutral in a new cabinet you will find that it is isolated.
Grounding terminals are attached to the chassis. but separate from the neutral.
Even in new cabinets the neutral does not touch the ground (Chassis), however; there is a bonding screw supplied with the cabinet. (green in color)
I am in the process of rewiring the utility that enters my house by SEC cable and the neutral is touching the cabinet chassis by a connector which creates bonding.
Bonding the neutral and the ground together causes problems with GFIC's.
They just do not work properly.


----------



## motormonkey (Jul 10, 2016)

New electrical panels do indeed come with the neutral conductor unbonded from ground, but they also include the provision to bond the conductors together if required by the installation, such as if the panel is to be used as a service panel. Please cite the section in the NEC that says that neutral and ground should not be bonded at a service panel or entrance.


----------



## iowagold (Jan 22, 2020)

they leave it up to the electrician to connect the neutral to the earth ground on any modern panel.
here is why.
the first panel in is the primary or main panel
this is the panel that needs to be bonded.
the sub panels and equipment that are down stream are un bonded.

so a panel off the shelf could be used as a master or main panel or as a slave or sub panel.
most mfg's provide a bond screw with the breaker panel these days or have them offered at an extra price.
i use square D QO series for the industrial stuff.
and yes the green bonding are provided in the panel kit.

I just set another 200 amp panel this last weekend.
just an update on an older 1930's built house.
good sized project, total gut out and rebuild.
It passed local inspection this am.
and utility is connected now.
and ready for the next phase of the rewire.


----------



## Bluwolf (Nov 8, 2020)

Sorry guys. Does this mean I still don't know whether to bond or float the neutral on the generator? Is there a way I can pull the front cover off the breaker panel and tell which way I should go?


----------



## Old man here (Nov 5, 2020)

Bluwolf said:


> My setup at home. Champion model 100296 dual fuel. I have an interlock. The 220 breaker is running to an inlet box on the other side of the wall. It's an L14-30 plug setup to the generator. This is what it says in my owner's manual:


Is this a sliding device in your breaker panel that only allows you to turn the generator feed breaker on if the main breaker is off?
You have to turn the main breaker off, slide a metal bracket, then turn on your breaker for the generator power?
Is your generator breaker inside the Breaker Panel a "two pole" breaker, like your water heater breaker?

Are you set up like this?
Utility Power Meter
|
|
Outside Main Disconnect----Neutral bonded to Ground here
|
| |Outside Generator Plug Socket
| |
I |nside Breaker Panel ----No Neutral bond!
| |
|--------Generator Breaker and Transfer Switch plate? {inside the Breaker Panel}
|
House lighting and appliances

If so, then your generator should have a "floating neutral".


----------



## iowagold (Jan 22, 2020)

plain ans is remove the bond at the generator from the green ground to the white.

make sure to mark the gen set as un bonded.


----------



## motormonkey (Jul 10, 2016)

Bluwolf said:


> Sorry guys. Does this mean I still don't know whether to bond or float the neutral on the generator? Is there a way I can pull the front cover off the breaker panel and tell which way I should go?


Pulling the cover will not tell you anything that you do not already know. Go back and reread my first post, particularly this paragraph, which describes the switching scheme you are employing by using your breaker/interlock:

"If you have a transfer switch which only switches the two line conductors between utility and generator to the load, the utility and the generator share a common neutral conductor. (the neutral conductor is not switched) In this case, the bonding point between the neutral conductor and the grounding conductor in the utility breaker box or meter box can serve both systems, regardless of the position of the transfer switch. *In this case, the neutral conductor in the generator should not be directly bonded to the grounding conductor.*"

Go into the generator and do what you have to do to remove any neutral/ground bond present there.


----------



## Bluwolf (Nov 8, 2020)

Okay, understood. I've watched the video I posted above. it's like a 5 minute job. The generator showed up yesterday, late afternoon. It's a refurb from Supergen Products. It looks virtually brand new. There is one little scuff on the black frame, a scuff of the paint, not even a scratch. If it runs half as good as it looks we'll be in good shape.

Thank you gentleman. As I mentioned, this is for work. I like my boss and I really want this to work out for the business. I'll let you know how everything works out.


----------



## somedumbguy (Sep 17, 2020)

Bluwolf said:


> Okay, understood. I've watched the video I posted above. it's like a 5 minute job. The generator showed up yesterday, late afternoon. It's a refurb from Supergen Products. It looks virtually brand new. There is one little scuff on the black frame, a scuff of the paint, not even a scratch. If it runs half as good as it looks we'll be in good shape.
> 
> Thank you gentleman. As I mentioned, this is for work. I like my boss and I really want this to work out for the business. I'll let you know how everything works out.


Here's a document at the Champion site that probably says the same thing as the video, if you prefer text (like me).
Microsoft Word - Neutral Bonding.doc (netdna-ssl.com)


----------

