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-   -   How to tell if my neutral is bonded to my ground? (http://www.diychatroom.com/f18/how-tell-if-my-neutral-bonded-my-ground-149212/)

simanco 07-04-2012 11:28 PM

How to tell if my neutral is bonded to my ground?
 
Howdy all,

My main panel has both neutral and ground bars. The ground bar is definitely bonded to the case - I can see the tightened-down green screw. But I see nothing bonding the neutral bar to the case or the ground bar.

It is a Westinghouse B20 3040CT. In an effort to keep the picture nice and large so ya'll can see some detail, I've posted it here:

http://cookingwithjim.simanco.net/wp...sub-panels.jpg

Can anyone tell?

Thanks,
Jim

Techy 07-04-2012 11:33 PM

those are technically both 'neutral' bars, when the panel was new there wouldve been some type of jumper between the two bars, and it may be behind the plastic at the top of the bars

Stubbie 07-05-2012 12:33 AM

Quote:

Originally Posted by Techy (Post 958261)
those are technically both 'neutral' bars, when the panel was new there wouldve been some type of jumper between the two bars, and it may be behind the plastic at the top of the bars

Did you look at the left side where the neutrals are terminated ? Looks like there is a #6 bare copper stranded terminated in some sort of insulated lug ?

It also looks like the left side neutral bar is broken where the lug is installed. It appears that the lug is screwed to the can thru a termination hole in the neutral bar at the point it is broken. I don't think the neutral bar above the break is part of the bond to the can. If that is the case there is no ground fault protection at all since all the egc's are terminated on the right hand side.

How do you see it?

simanco 07-05-2012 12:37 AM

The stranded copper is part of the feed to a sub-panel in the upstairs - fed by the 60-amp double pole at the top of the left-hand column of breakers - exiting the top of the panel.

The bar is definitely not broken, although that lug is spanning three of my neutral spaces.

Jim

Techy 07-05-2012 05:53 AM

Standard 'Add-a-Lug' for wires that don't fit in the regular holes.


I dont see any visual bonding between the two bars in your pictures.

zappa 07-05-2012 06:15 AM

I couldn't find any information or pics for this panel. If you have an accurate ohm meter I would turn the main off to hopefully keep small voltages from messing with your readings and measure between the neutral and ground bars. If they are bonded at this panel the resistance should be as low as touching your leads together. When making small resistance readings I always touch the leads together first to give me a base line.

I see a couple of neutrals doubled up probably because of that big lug. :wink:

jbfan 07-05-2012 08:32 AM

If you look under the main breaker, under the black is a strip that connects both bars to each other.
Based on what I see in the picture, it looks bonded to me.

joed 07-05-2012 09:24 AM

I see several neutral holes that appear to have two wires in them.
If that feed to the sub panel is only three wires that is wrong also. Being in the same building it should have a four wire feed and the neutral ground not bonded in the sub panel.

Stubbie 07-05-2012 10:14 AM

Quote:

Originally Posted by Techy (Post 958343)
Standard 'Add-a-Lug' for wires that don't fit in the regular holes.


I dont see any visual bonding between the two bars in your pictures.

Yes I agree, after blowing the picture up for a better look. My concern wasn't the added lug I thought the dang bar was broken.

I'm not familiar with that panel but I would have to agree with JBfan that a metal strap extends between bars and is underneath that black plastic channel. there are other panels just like that.

I'd say the panel is correctly bonded but I'd like some clarification on the green bonding screw... I'm not sure I see it.

Yoyizit 07-05-2012 10:20 AM

First check for voltage between the neutral and ground bar. If the voltage is more than a few millivolts you probably don't have a bond but zero volts doesn't mean you are bonded.

Then you could use one of these battery/incand. lamp continuity testers if your meter is not protected against overvoltages on the ohms scale.

jrclen 07-05-2012 12:00 PM

I think I see the bonding screw two thirds of the way down on the right hand terminal strip. I agree with the others that the strips are bonded together at the top by a bar running under the plastic between the two of them. If so, this is fine.

What I don't see is a neutral conductor for the sub panel you mentioned.

And I see a couple doubled up neutrals which can be separated as there seems to be unused terminals on that side.

simanco 07-05-2012 12:18 PM

Thanks all ...

The green bonding screw: count down 5 breaker spaces and look directly across to the right on the "ground" bar. You can barely see the green screw hiding between the black and white No. 8 wires.

The doubled-up neutrals have been fixed since that picture was taken. THOSE were put in by a licensed electrician (back when there were obviously FREE neutral spaces) AND the inspector signed off on it! <sigh> Of course they also signed off on 3 lighting circuits that have 20-amp protection and I'm nearly 100% certain that I've seen No. 14 in some of the boxes over the years. (Yes, I have the 15 amp breakers to fix that.)

The sub-panel feed is 4-wire, #6 with ground with a 50amp breaker protecting.

It has occurred to my feeble mind that there is a label with a diagram on the door of the panel. But I'm still confused. It appears to show that the two bus bars are joined under that black plastic strip, but it also says to bond the "neutral" bar when required. Here is a huge picture of the panel label:
http://cookingwithjim.simanco.net/wp...anel-label.jpg

Given that diagram, what's the verdict? Bonded or not bonded?

Thanks again,
Jim

simanco 07-05-2012 12:33 PM

Ooops, let me clarify regarding sub-panels. There are two, obviously. There is one that is sitting beside the main, which is the one with a 4-wire feed fed by a 50amp breaker.

The other is an ancient fuse box in the upstairs of the house, dating from years ago when the upstairs was an apartment. It is fed by that 60amp breaker on top of the left hand row of breakers. Without going to the basement to check, I can't say off-hand if there is a 4th wire, but considering the bare, stranded copper is lugged onto the left-hand "neutral" bar, I'm guessing now.

Again, that fuse box was connected to this panel by a licensed electrician and passed inspection. (1991 when the service was upgraded to 200 amps.) Can you tell I'm bitter?

The original 2-wire Romex in this house appears to have been done professionally and neatly and ... it just "looks well done." Then there was a set of nit-wits re-doing the house after a flood in 1977. Nearly every wall in the house was down to studs. It didn't get rewired. They only spliced in bits of 3-wire Romex (12-2 with ground) and added in grounding outlets. The splices are twisted and electrical taped and buried everywhere. Yesterday I found about 6 feet of live, un-capped, simply cut-off, 2-wire Romex just hanging out in a wall. The hot side of that appeared to have melted insulation at the end of it; I don't want to think about it!

Thanks,
Jim

Stubbie 07-05-2012 03:49 PM

Quote:

Originally Posted by simanco (Post 958539)
Thanks all ...

The green bonding screw: count down 5 breaker spaces and look directly across to the right on the "ground" bar. You can barely see the green screw hiding between the black and white No. 8 wires.

The doubled-up neutrals have been fixed since that picture was taken. THOSE were put in by a licensed electrician (back when there were obviously FREE neutral spaces) AND the inspector signed off on it! <sigh> Of course they also signed off on 3 lighting circuits that have 20-amp protection and I'm nearly 100% certain that I've seen No. 14 in some of the boxes over the years. (Yes, I have the 15 amp breakers to fix that.)

The sub-panel feed is 4-wire, #6 with ground with a 50amp breaker protecting.

It has occurred to my feeble mind that there is a label with a diagram on the door of the panel. But I'm still confused. It appears to show that the two bus bars are joined under that black plastic strip, but it also says to bond the "neutral" bar when required. Here is a huge picture of the panel label:
http://cookingwithjim.simanco.net/wp...anel-label.jpg

Given that diagram, what's the verdict? Bonded or not bonded?

Thanks again,0Jim

If this is indeed the service equipment then can and equipment grounding looks bonded to neutral and the diagram answers my questions.

Where is the grounding electrode conductor? ... either for metal water pipe or ground rod or other ?

simanco 07-05-2012 11:37 PM

1 Attachment(s)
The grounding electrode is under the new meter box. You should be able to see it in the attached picture.

I can't see any copper coming into the panel but there is so much copper in that corner it could still be hiding from me. Is it possible to ground the panel via all that metal conduit shown in the picture?

Jim


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