Sub-panel connected to main via conduit...

[Jeffrey]

The bond screw should be used in the sub-panel since you are physically/electrically connecting the main and the sub-panel via the conduit, correct? I'm using a 2"x8" conduit btw.

An electrician already told me to do this but I just wanted to make sure. Personally I think it makes sense, but you can never be to careful so I thought I'd ask here also. ;)

TIA. :tree:

[Daniel Hall]

If it a sub panel fed off the main service (panel), you do not use the bonding screw in the sub panel, you only bond your main service once, after that the Neutral and Ground are kept separate.

[Jeffrey]

Hmmm... I almost wish I didn't use conduit because that is the point of confusion for me.

The electrician friend of mine said that connecting the two panels via conduit made the two panels basically into one as far as code goes so I should use the bond screw in the sub. Maybe he misunderstood me but he said this is common and seemed like he was completely sure of his answer.

I think I'll wait for another response or two and then maybe show him a picture of what I'm talking about. Like I said, maybe he misunderstood. :)

[Daniel Hall]

The conduit between the two panels is now your ground path between the sub panel and the main service, that is if you used a metal conduit, if it isPVC then you would need a ground wire.

It's not the conduit, it because it's a Sub Panel, fed from your main service, only the Main service do you bond the neutral to the ground.

[Tony Furst]

The conduit does become part of your bonding and grounding path, however you are still required to have a properly sized ground wire from your main panel to your sub panel.

As for the bonding jumper or screw you do not bond the neutral in your sub panel, the NEC does not allow an exception when the panels areconnected by conduit.

What your electrician friend may be thinking of is parallel main panels where you have two panels side by side fed from a single main breaker. In this case yes the neutral bar in both panels gets bonded because from a code perspective it is one panel.

Tony

[Jeffrey]

Tony Furst wrote:
What your electrician friend may be thinking of is parallel main panels where you have two panels side by side fed from a single main breaker. In this case yes the neutral bar in both panels gets bonded because from a code perspective it is one panel.

Tony

Maybe. I'll talk to him about this next time I see him. First thing first though, time to get that bonding screw out of there. ;)

And thank you for the input Daniel and Tony... it is much appreciated. :happytree:

[inspector4]

If I understand your question correctly, you are installing a sub panel directly adjacent to your main panel. The answer is maybe. The neutral (white) wires in the sub panel should be landed on a buss that is isolated from the enclosure. The grounding (green/ bare) wires should be landed on separate buss bar. This grounding buss bar (with green /bare wires) should be bonded to the sub panel enclosure. By the NEC, the physical grounding path from sub panel to main panel can be a conductor (green or bare) or a metallic raceway.

Different manufactures have different basic set ups. If the panel is supplied with 2 buss bars, make sure they are physically isolated from each other. If both are isolated from the enclosure, you may install the green screw in one buss after verifying that it is isolated from the other buss and use it for your grounding terminations.

When In doubt, contact that qualified person.

Just my 2 cents.



Steve

[inspector4]

Off topic but…….. As a newbie, is this rude to post in larger print?

I find it so much easier to type in a “Word” document, spell check, and paste it here.

And I find the larger print easier on my old eyes.



Steve

[Daniel]

inspector4 wrote:
Off topic but…….. As a newbie, is this rude to post in larger print?

I find it so much easier to type in a “Word” document, spell check, and paste it here.

And I find the larger print easier on my old eyes.



Steve


I cant help with the sub panel, but to answer the above question. Yes, font size is not a problem, just try to keep it to a reasonable size. :laughing: fonts and sizes mix things up, I personally like to read posts that have formating, although I rarely format my posts.




--Daniel L

[Jeffrey]

inspector4 wrote:
If I understand your question correctly, you are installing a sub panel directly adjacent to your main panel. The answer is maybe. The neutral (white) wires in the sub panel should be landed on a buss that is isolated from the enclosure. The grounding (green/ bare) wires should be landed on separate buss bar. This grounding buss bar (with green /bare wires) should be bonded to the sub panel enclosure. By the NEC, the physical grounding path from sub panel to main panel can be a conductor (green or bare) or a metallic raceway.

Different manufactures have different basic set ups. If the panel is supplied with 2 buss bars, make sure they are physically isolated from each other. If both are isolated from the enclosure, you may install the green screw in one buss after verifying that it is isolated from the other buss and use it for your grounding terminations.

When In doubt, contact that qualified person.

Just my 2 cents.



Steve



Excellent information there. Exactly the scenario I was trying to describe. The sub-panel is about 6" to the left of the main connected via 2" metallic conduit.

I have removed the bonding screw that tide the neutral bus to the ground bus so they are indeed separate. Only place they are tied together is the main.

Thanks again for all the good information. :waycool: