diy solar

diy solar

Need professional advice on main service panel wiring.

Rocknemo

New Member
Joined
Jan 3, 2021
Messages
89
I've researched extensively and I believe my main panel is not properly configured. I'm in the process of adding a sub panel for my offgrid solar and after opening my main panel I have verified that both the neutral and ground are tied together and all are bonded to the panel box. My main panel is in the garage at the other end of my house from the meter can. At the meter can there is a whole house disconnect panel where main power comes in along with the earth ground. The house is 30+ years old here is Florida. After everything I've seen my main panel in the garage should be considered a subpanel with the ground and neutral being isolated. Just hard to believe this is wired incorrectly from a new build 30 years ago. There are two green screws installed right at the busbar's of the Neutral and ground. Should these be removed? Expert advice would be greatly appreciated. Thanks

I tried adding some pics of my main panel.
I guess the picture files are to large to post
 
Very interested in this thread. At my cabin there is a meter with a disconnect 200amp breaker about 100ft from house on a utility pole. There is a G/N bond there. In my main panel there is also a G/N Bond. My newly setup critical loads panel is not bonded.

The G wire coming into house panel is NOT in the conduit with the 2 hots and N. Just run separately. I can’t tell if that solid G wire is the same as the one at the meter.

The pic shows the ground wire that is bonded before at the N when going into conduit to the house. Simply can’t tell if that’s the same In main panel or not. Again about 100ft from this panel to house. 27207F91-283E-4729-9217-CC46392B03CA.jpeg
 
Last edited:
OP, your main panel is wired correctly. grounds and neutrals must be bonded in the USA. so no, don't change anything. subpanel should be the same. grounds to ground bus and neutral to neutral bus.
 
There is a G/N bond there. In my main panel there is also a G/N Bond.
I see what appears to be a rather small gauge insulated wire going down the post.
Also the insulation does not appear to be green.

I don't see a neutral/ground bond.

Having more than 1 n/g bond means you will have service current on the grounding conductor, which is dangerous.
Having no n/g bond means a ground fault is much less likely to trip a breaker thus clearing the fault, which is dangerous.
 
Last edited:
To the OP (in the USA) The first panel downstream of your meter would be your "main" panel, and the neutral would be bonded to the sheet metal of the box using those green screws. You'll even see ground wires landed on the neutral bar because at that point it's all the same electricially. Now any panel after that the neutral and ground are kept insulated from each other. (do NOT connect them together)
(Retired Master Electrician)
 
I see what appears to be a rather small gauge insulated wire going down the post.
Also the insulation does not appear to be green.

I don't see a neutral/ground bond.

Having more than 1 n/g bond means you will have service current on the grounding conductor, which is dangerous.
Having no n/g bond means a ground fault is much less likely to trip a breaker thus clearing the fault.
I’m telling you under the panel that uninsulated conductor is bonded to the 4/0 neutral conductor going to the house via conduit. There is no current on that conductor validated with ammeter.

How can I easily tell if that is the same G conductor going to Main panel 100 ft away.
 
To the OP (in the USA) The first panel downstream of your meter would be your "main" panel, and the neutral would be bonded to the sheet metal of the box using those green screws. You'll even see ground wires landed on the neutral bar because at that point it's all the same electricially. Now any panel after that the neutral and ground are kept insulated from each other. (do NOT connect them together)
(Retired Master Electrician)
Thanks for replying for Mike, its very good hearing from a Master Electrician. So just to re-verify what you are stating, my main panel is correct in having both the Neutral and Ground bussbars tied together and those all bonded to the case? And my new manual transfer subpanel should have them both isolated?
 
I’m telling you under the panel that uninsulated conductor is bonded to the 4/0 neutral conductor going to the house via conduit.
Out of curiosity what guage is that wire?
There is no current on that conductor validated with ammeter.
That wire is probably after the final n/g bond and would not normally have much current on it.
Its mostly just a drain to the dirt for electricity that didn't originate at the transformer.
Even if there is fault current it should be going back to the transformer via the neutral.
The purpose of the n-g bond is to provide a low impedance path back to the transformer.
However if there is no n-g bond the path back to the transformer is through grounding electrode.

How can I easily tell if that is the same G conductor going to Main panel 100 ft away.
Since there is a Retired Master Electrician participating in the thread I will take a step back.
@Mike 134 if I've said anything wrong please correct me, I won't be offended.

Fun fact: The path back to the transformer can be from your grounding electrode to your neighbor's grounding electrode then back through his neutral to the transformer.
 
And my new manual transfer subpanel should have them both isolated?

your main to subpanel line becomes your subpanel feed. ground to ground bar, neutral to neutral bar. do not bond in the subpanel. bonding screw (if exists) must be removed. good video here -- start at 14mins --
 
Your Main in the house will have neutral bonded to the ground. Yes the disconnect at the pole has a neutral ground bond per code. As does every single overhead pole running to your place. Go out and look and you will see a heavy bare copper wire running down the pole with it tied into the neutral utility wire. At the bottom of the pole is a copper disk that the wire is attached to.

People over think neutral-ground bonds.
 
D8617D08-85F5-491C-AF4B-BB158AA69A1C.jpegWish I had a better picture. Out of the meter side a thick metal bar has the 4/0 N conductor attached to it that goes to house as well as that bare metal ground conductor. The bare metal conductor attached to pole, 4/0, and thick metal bar are all tied together under the right panel just below the switch. The two hots and N go into conduit in the house.

At the house panel there is a a ground that goes outside and down into the dirt. Wonder if this ground conductor is the same coming from cutoff panel bonded to N at the meter area

The transformer is on a different pole about 20 ft away that has its own ground wire attached to the pole.
 
Last edited:
Wow! That is one corroded service panel. I would replace that if I was you.
It will be but that is not my question. Do the experts think ground should be bonded here AND in my Main Service Panel in the house. Again, can’t tell if it’s the same wire.
 
Fun fact: The path back to the transformer can be from your grounding electrode to your neighbor's grounding electrode then back through his neutral to the transformer
That wouldn't be considered a low impedance path.
Just a bad backup plan.
 
View attachment 104042Wish I had a better picture. Out of the meter side a thick metal bar has the 4/0 N conductor attached to it that goes to house as well as that bare metal ground conductor. The bare metal conductor attached to pole, 4/0, and thick metal bar are all tied together under the right panel just below the switch. The two hots and N go into conduit in the house.

At the house panel there is a a ground that goes outside and down into the dirt. Wonder if this ground conductor is the same coming from cutoff panel bonded to N at the meter area

The transformer is on a different pole about 20 ft away that has its own ground wire attached to the pole.
If I have understood correctly. There's only 3 wires going from the pole mounted box, to your "main" panel inside the garage.
The original installer treated this pole mounted box as a meter only. And the garage panel as the main.
Everything must remain as is, unless you want to replace the wiring between the two panels with 4 wires. (Because there's no grounding conductor between the outside and inside panel)
 
If I have understood correctly. There's only 3 wires going from the pole mounted box, to your "main" panel inside the garage.
The original installer treated this pole mounted box as a meter only. And the garage panel as the main.
Everything should remain as is. (Because there's no grounding conductor between the outside and inside panel)
Thanks @timselectric. Correct 3, conductors (L1/L2/N) are in conduit from this panel to main service panel in cabin (basement). There is a ground conductor not in the conduit. This outside panel is a disconnect where a N/G bond is AND there IS a N/G bond in my main service panel. Want to make sure it’s OK that the N/G is OK in both locations (over 100 ft apart). Just can’t tell if this ground wire is one in the same at this panel and house panel. No current on either validated by ammeter. I know that you’re only supposed to have one N/G bond. Can’t get a licensed electrician to property easily to 1)replace this rusty thing and 2)answer questions. Appreciate any assistance.
 
Thanks @timselectric. Correct 3, conductors (L1/L2/N) are in conduit from this panel to main service panel in cabin (basement). There is a ground conductor not in the conduit. This outside panel is a disconnect where a N/G bond is AND there IS a N/G bond in my main service panel. Want to make sure it’s OK that the N/G is OK in both locations (over 100 ft apart). Just can’t tell if this ground wire is one in the same at this panel and house panel. No current on either validated by ammeter. I know that you’re only supposed to have one N/G bond. Can’t get a licensed electrician to property easily to 1)replace this rusty thing and 2)answer questions. Appreciate any assistance.
The ground conductor going down the pole is an earth bonding wire. (Not a N/G bond) the N/G bond was installed at the garage panel. This is where "your" grounding system begins. It's a rare setup, but perfectly fine. This is the way it was done sometimes , many years ago.
 
Back
Top