N-G Bonding

[Anteclansing]

Hi everyone,

I have recently built an off grid solar system 6.5kw with an all in one hybrid inverter/charger. From the inverter I run 3 wires, 120v single phase, to a subpanel (could be thought of the main panel as I don't have any other panel) which has 2 breaker slots. I put 2 x 20amp breakers and run them out to 2x 20amp surge protectors. Long story short, I am producing more energy than I need so I want to use the excess to charge my tesla. However, when I plug in my mobile tesla charger, I get a ground fault. Basically the charger requires an N-G bonding. I am assuming my inverter, SRNE inverter does not have a built in N-G bonding mentioned any where. My subpanel is grounded. I was watching some youtube videos and people said to buy

https://www.amazon.com/dp/B07F4R7BDL?psc=1&ref=ppx_yo2ov_dt_b_product_details

which is an N-G bonding plug and plug it into my surge protector. It works for charging the tesla. But now I am worried about the safety of my system. I did not bond N-G in my panel, do I have to? Doesn't this compromise the grounding path as neutral is bonded to ground? Thanks so much in advanced. But should I keep using the bonding plug mentioned above?

 

[Nobodybusiness]

Hi everyone,

I have recently built an off grid solar system 6.5kw with an all in one hybrid inverter/charger. From the inverter I run 3 wires, 120v single phase, to a subpanel (could be thought of the main panel as I don't have any other panel) which has 2 breaker slots. I put 2 x 20amp breakers and run them out to 2x 20amp surge protectors. Long story short, I am producing more energy than I need so I want to use the excess to charge my tesla. However, when I plug in my mobile tesla charger, I get a ground fault. Basically the charger requires an N-G bonding. I am assuming my inverter, SRNE inverter does not have a built in N-G bonding mentioned any where. My subpanel is grounded. I was watching some youtube videos and people said to buy

https://www.amazon.com/dp/B07F4R7BDL?psc=1&ref=ppx_yo2ov_dt_b_product_details

which is an N-G bonding plug and plug it into my surge protector. It works for charging the tesla. But now I am worried about the safety of my system. I did not bond N-G in my panel, do I have to? Doesn't this compromise the grounding path as neutral is bonded to ground? Thanks so much in advanced. But should I keep using the bonding plug mentioned above?

You probably need to run a ground and bond to the neutral at the main panel of that system.
Whatever you are calling it. Main, sub panel..

Sub panels are not supposed to be bonded.

Did you ground your inverter?
Not familiar with that brand.
Does it not bond there?

Neutral and Safety Ground should be bonded at one point only in the system and should be done as close to the power source,

 

[Anteclansing]

You have no ground in that system at all?

You need to run a ground and bond to the neutral at the main panel of that system.

Hi. I do have a ground at the panel as mentioned. But neutral isn’t bonded to ground inside the panel.
1. Do I HAVE TO bond neutral and ground inside the panel?
2. If yes, can I bond them using the bonding plug mentioned?
3. My electrician friend told me that bonding neutral and ground would negate the ground as when there is a fault grounding wont do grounding work anymore if bonded to neutral. Excess current won’t have a place to go. Is this true?

 

[Nobodybusiness]

Hi. I do have a ground at the panel as mentioned. But neutral isn’t bonded to ground inside the panel.
1. Do I HAVE TO bond neutral and ground inside the panel?
2. If yes, can I bond them using the bonding plug mentioned?
3. My electrician friend told me that bonding neutral and ground would negate the ground as when there is a fault grounding wont do grounding work anymore if bonded to neutral. Excess current won’t have a place to go. Is this true?

Hmmm.

Not sure why it would negate the ground.

NEC states
“Neutral and Safety Ground should be bonded at one point only in the system and should be done as close to the power source,“

I know Tesla chargers are very particular about the bond.
Believe those Tesla charges check the N-G bond and if they don’t see it they won’t work.

There are more than a few Electricians on here.
I’m sure one of them will chime in.

 

[Anteclansing]

Hmmm.

Not sure why it would negate the ground.

NEC states
“Neutral and Safety Ground should be bonded at one point only in the system and should be done as close to the power source,“

I know those Tesla chargers are very particular about the bond.
I believe this Tesla charges check the N-G bond and if they don’t see it they won’t work.

Not sure if that plug will help or not.


There are more than a few Electricians on here.
I’m sure one of them will chime in.

Hi. I bought the plug and used it and it works. That means without the plug my system obviously doesn’t have NG bonding. So the plug did the NG bond. But my question is that ok? Or do I bond at panel level because the plug is plugged into the surge protector.

 

[Nobodybusiness]

Hi. I bought the plug and used it and it works. That means without the plug my system obviously doesn’t have NG bonding. So the plug did the NG bond. But my question is that ok? Or do I bond at panel level because the plug is plugged into the surge protector.

That’s what it appears to do.

It is bonding the ground and neutral at the plug.

Is this how you Should run it?
Is it safe?
It’s not what I would do but thats neither here nor there.

I guess if we want a definitive answer then probably have to wait on one of the Sparkys to comment.

@timselectric care to comment?

 

[Anteclansing]

So I have two surge protectors on two different breakers, so that means two different circuits, and I tested the charger with them both and they both worked. That means that one plug in only one of the surge protectors provided NG bonding for the entire system? So that means it’s not only bonding at the plug right?

 

[Nobodybusiness]

So I have two surge protectors on two different breakers, so that means two different circuits, and I tested the charger with them both and they both worked. That means that one plug in only one of the surge protectors provided NG bonding for the entire system? So that means it’s not only bonding at the plug right?

Well the bond is at the plug but it is doing the same thing as bonding it at the panel.

You just moved it from the panel to the plug.

If It were me I would just bond the N-G in the panel or the inverter if it will bond there.
If that plug get pulled or knocked out then you no longer have any bonding.

It’s not what I would do but for an official NEC answer have to wait on the guys who know for sure.

 

[rodrick]

I think your creating the ng with the plug adapter and I would be concerned about the system being properly grounded if there is no ng bond in the inverter the bond should be in the breaker box and also connected to the 2 ground rods making a proper grounded system imo

 

[Nobodybusiness]

I think your creating the ng with the plug adapter and I would be concerned about the system being properly grounded if there is no ng bond in the inverter the bond should be in the breaker box and also connected to the 2 ground rods making a proper grounded system imo

I agree.

Not familiar with the SRNE inverter.
Not sure if you ground the inverter it will bond there or have to do it at the panel.

 

[rodrick]

I agree.

Not familiar with the SRNE inverter.
Not sure if you ground the inverter it will bond there or have to do it at the panel.

I not familiar with SRNE either, I’m guessing because it works with his adapter that the inverter is not ng bonded

 

[Nobodybusiness]

I not familiar with SRNE either, I’m guessing because it works with his adapter that the inverter is not ng bonded

Or he doesn’t have a ground running to the inverter.

 

[timselectric]

The inverter is not providing the N/G bond.
I don't know if it has a setting to do it. But I would recommend that it be done at the main panel. As it's the first means of disconnect. (This is the NEC required location)

My electrician friend told me that bonding neutral and ground would negate the ground as when there is a fault grounding wont do grounding work anymore if bonded to neutral. Excess current won’t have a place to go. Is this true?

No, it's not. (Not even close)
Your friend is not an electrician, yet.
They definitely have more to learn.

While the bonding plug is working. I wouldn't trust it at the surge protector. You are counting on too many parts of the system to be functioning, to provide the grounding system.
The electrical grounding system is created by, and begins at the N/G bond.

 

[hpeyerl]

I'm currently building up my own system and am confused by this.

I have a power pole in my yard, with a transformer at the top and a meter base at the bottom. Below the meter is where I, the homeowner, can take power. I had two runs come off this, one to the house, and one to the shop. The house and shop each have their own ground plates/rods. 10 years ago, a master electrician came over and told me the meter base is the main panel and that's where the bonding happens. Every panel downstream is a sub-panel. The inspector agreed and specifically checked that my house and shop panels were not bonded (even though they had their own ground plates/rods and were connected to the pole via USEB-90 which has no ground conductor.

Now that I'm doing my own PV+AIO+Battery system, I had an electrician come by to look over my plan and he told me that I have to assume the pole doesn't exist so each panel that is connected directly to the pole is considered a service entrance and needs to be bonded at that point and that the local inspectors will fail it if they are not bonded.

So now I don't know what to think. I want think that wherever a panel is connected via USEB-90, there needs to be a ground plate and that panel needs to be bonded. But I'm not an electrician.

 

[Mattb4]

... I am assuming my inverter, SRNE inverter does not have a built in N-G bonding ...

I would not assume this unless you have one that has a setting to disable NG bonding. Some of these units are not great at bonding though and require a jumper from the case ground to the "AC in" ground terminal as well as the proper connection to Earth ground. You do not mention your inverter model. Some use case ground screw as the AC out ground, these in particular need the jumper.

 

[timselectric]

I'm currently building up my own system and am confused by this.

I have a power pole in my yard, with a transformer at the top and a meter base at the bottom. Below the meter is where I, the homeowner, can take power. I had two runs come off this, one to the house, and one to the shop. The house and shop each have their own ground plates/rods. 10 years ago, a master electrician came over and told me the meter base is the main panel and that's where the bonding happens. Every panel downstream is a sub-panel. The inspector agreed and specifically checked that my house and shop panels were not bonded (even though they had their own ground plates/rods and were connected to the pole via USEB-90 which has no ground conductor.

Now that I'm doing my own PV+AIO+Battery system, I had an electrician come by to look over my plan and he told me that I have to assume the pole doesn't exist so each panel that is connected directly to the pole is considered a service entrance and needs to be bonded at that point and that the local inspectors will fail it if they are not bonded.

So now I don't know what to think. I want think that wherever a panel is connected via USEB-90, there needs to be a ground plate and that panel needs to be bonded. But I'm not an electrician.

The way it was originally installed is correct.
The N/G bond should be at the first means of disconnect. The ground plates have nothing to do with the N/G bond. They are just earth connections. That were required at each building.

 

[hpeyerl]

The way it was originally installed is correct.
The N/G bond should be at the first means of disconnect. The ground plates have nothing to do with the N/G bond. They are just earth connections. That were required at each building.

So to be perfectly clear, the N/G bond should be at the meter base at my pole and every other panel in the system should be not bonded; regardless of whether there is 3 or 4 conductors running to that panel.

 

[Anteclansing]

The inverter is not providing the N/G bond.
I don't know if it has a setting to do it. But I would recommend that it be done at the main panel. As it's the first means of disconnect. (This is the NEC required location)

No, it's not. (Not even close)
Your friend is not an electrician, yet.
They definitely have more to learn.

While the bonding plug is working. I wouldn't trust it at the surge protector. You are counting on too many parts of the system to be functioning, to provide the grounding system.
The electrical grounding system is created by, and begins at the N/G bond.

Thank you so much for this. I have attached the manual for my inverter and the model is HF4850U80-H. My one and only panel IS grounded. I don't see N-G bonding in the manual. It does have a ground screw on the box. Do I have to also run a ground cable to a separate grounding rod from the inverter? If it wasn't for the Tesla charging, I would have been running WITHOUT an N-G bond forever. I used it without the N-G bond for almost half a year. If I may ask a few questions:
1. There are 3 cables running from the inverter AC out L-N-G so I thought that grounding the panel would automatically ground the inverter as inverter and panel are bonded.
2. I also have an array of solar panels that I use to charge the batteries and last week when I was cleaning them I got shocked. They are not bonded/grounded. Do I have to ground them? And also bond them at their frame? They are connected so I thought they are bonded automatically?
3. Does bonding N-G at the electrical panel mean get a wire and connect neutral and ground? I thought neutral is the current carrying path and ground is only current carrying path in case there is a fault, but if I connect them does that make ground the current carrying path as well?

Thank you so much!

 

[Anteclansing]

Also,

4. The inverter has AC charging capability as well, so If I bond N-G and connect the AC charging, that will create 2 N-G bonds. Wouldn't that be very bad?

 

[B-Mod]

So to be perfectly clear, the N/G bond should be at the meter base at my pole and every other panel in the system should be not bonded; regardless of whether there is 3 or 4 conductors running to that panel.

Is there a panel at your pole location? Some pictures would really help show what you have existing.