Neutral and Ground Separation

[HayZee518]

The elements are connected across both 120 volt legs = 240. The light inside and the clock timer are 120 volt. They connect across one leg to the neutral or in this case the bare ground. So what you're reading is the return to ground through the device. By me touching the bare wire and the grid I was completing the path to EARTH ground before the path it would normally take to the main panel. I was a better path than that floating bare ground in the panel.

[Kidd6488]

Oh I see, the impedance of the 120V components were giving you 120V. I was thinking this was a range outlet, and the range was unplugged. I understand now.

~Jonathon Reinhart

[Kidd6488]

If this helps anything, here are pictures of our MAIN disconnect box, and breaker box.



Here's the neutral lug, with a third lug, and bonding screw hole. Would this be the way to bond the system neutral to ground? It's a 10-32 screw which the installers lost, so we would have to get a new one. Or, would I just run a large (#6?) wire from that third little lug and clamp on to (with a split-bolt lug) one of the other ground wires in the disconnect?



And here's our panel box, with ground bar on left, and neutral bar on right.



~Jonathon Reinhart

[Rewired]

You are right about there being or could be several ohms in the grounding path back to the transformer. You are correct there as well, a fault current is going to try to return to the transformer, NOT just "into the earth", it will use the path through the earth if its easiest. Oh ya, I see your pictures now. To make the bond in the disconnect I would use a BRASS screw in the place where the original one was located.. Usually the ones I have seen are brass..

One experience of several I had with wierd / bad grounds was a few years ago, I was doing a panel change at the neighbours across the street, and had the 2 hot wires and bare neutral (yes, it was allowed here) hanging out of the LB fitting at the side of the house, and was about to disconnect the old ground and remove the old panel from the wall (keep in mind the panel was still in contact with "ground" through the metal conduit, where it is also bonded in the meter socket!
Anyways, I unhooked the old ground to the water pipe and got a nice arc!
I connected it back and did a load check and found out there was 7 amps cruising OUT of the water pipe and up the service , back to the transformer! Keep in mind there is NO POWER present in the building as the meter was unplugged from its socket!
The only reason I can see this happening is someone in the court must have a bad neutral in their service, and any unbalanced neutral current is going through their bonding jumper, through the grounding conductor, to the metal water pipe, under the street, up the water pipe of the house I was in, and back up the service to the transformer! (the house I was in was closest to the poletop transformer.. Sounds a bit wierd eh? I have seen this sort of thing several times!

A.D

[HayZee518]

Could be a fault on a device and the unbalanced load is just taking the easiest path back to ground. As a rule if a fuse is put in between the grounding conductor and the ground rod - if it blows - there's a problem because there should be NO potential on the grounding wire.

[HayZee518]

6 amp fuse.
Who's the guy that just shoved that 1 inch pvc conduit into the box?? No adapter with locknut - and - what about the two wires just connected across the face of the panel?? Hmmm?

[Kidd6488]

There's no 1" PVC. If you're talking about the gray in the center above the box, that's the mains coming down, and were slightly bent. It's in romex fitting, and tightened down, its just at a mean angle in the attic. The other 2" Conduit is in there properly with adapter, locknut, AND bushing. Those other two wires won't be there for long. They're just running our well and water heater for now until we get all our water works situated on the other side of the garage. We'd never leave anything like that (although I know some people who would...).

So 10-32 brass screw in the main disconnect, and keep the neutral and ground separate everywhere else...

Thanks!

~Jonathon Reinhart

[Dan44057]

I have a question along these lines??

1. Is it permissible to have a subpanel, that has a ground wire back to the main panel, to also have a ground rod? If not why?

2. If I three seperate barns away from my house, and I run 3 -2/0 wires in PVC to each one, and I put a ground rod in at each "subpanel" at each separate barn, do I also bond the netural at the subpanel?? or do I simply ground the subpanel cabinet??

Thanks for your help.

[HayZee518]

the three ground rods will terminate at an aux ground bar. the neutrals are not bonded to the cabinet. (isolated)
Kidd panelbox photo - just left of the main seu - there's a pvc adapter coupling that's just shoved through a knockout

[Kidd6488]

wouldn't dan need to run the 3 2/0's and a smaller 4th wire for ground?

and also, there's only one conduit coming in this box. It's 2" PVC, with the proper adapter coupling, locknot, and insulating bushing (I think It's called). If you look closely, you can see the little ridges on the bushing in the box.

~Jonathon Reinhart

[Kidd6488]

Here you can see that conduit properly installed.





Also, for our 100A subpanel to our barn, we've run 2-2-2 XLPE / USE-2 (twisted stuff). Will we need to pull a 4th wire out for equipment ground?

~Jonathon Reinhart

[MattCarp]

Just want to let you guys know that this is a great thread. I am dealing with EXACTLY the same thing and you've answered questions about my home wiring.

Specifically, I have a "standard" 200A service and completely full main panel. Similar to Jonathans, I have a neutral bus bar on the right, and the opposite bus bar is used as a ground bus bar, bonded to the enclosure. The jumper bar between bus bars is missing.

I had to double check - my neutral is bonded to ground at the service disconnect.

I am installing a subpanel right next to the main panel to support the wiring of my basement that I am converting to finished space.

I've put in a 125A subpanel and will be connecting it to the main panel with 2-2-2-4 aluminum wire.

In the subpanel I'll keep the neutral bus bars jumpered and I've added an equipment ground to the enclosure (GE part #TGK24). This new ground bus bar attaches right to the enclosure. The ground from the main panel will attach to this ground bus bar.

Now, to complete the project, I just need to install a couple 100A single pole breakers into the main panel to connect the hots for my subpanel, and wire my ground and neutrals into the bus bars of the main panel. Sound good?

[Kidd6488]

Yep,sounds good. The subpanel will be good for 100A. But in the main panel you will need to install ONE 100A Double-Pole breaker. (I don't think they even make 100A single-pole breakers.) For a 240V subpanel, the two legs need to disconnect simutaneously, hence the little bar between the to handles on the double-pole breaker.

I was hoping someone would reply about the barn sub-panel, but I think I've pissed some people off, as no one but MattCarp has replied in 8 days...

~Jonathon Reinhart

[Kidd6488]

Hey, Just wanted to again thank everyone for your help in this post. Hayzee - I think I owe you an apology. I read through everything and realized I was quite cocky.

Thought I might add, we have pulled a #4 4th-wire-ground out to the barn, and everything is the way it should be!

Thanks again.

Jonathon Reinhart
jonathon.onthefive.com

[HayZee518]

you're welcome. I got kinda cocky too. sorry