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Bonding of nuetrals and grounds.

New postPosted: Wed Apr 21, 2021 9:39 am
by bigdog
Newer house permitted in 2016 in Palm Beach county. Eaton distribution panel (sub panel). So Eaton has those straps that connect both neutral bars and all of the neutrals are connected to them and it has a separate ground bar for the grounds.........but the neutral bars are also bonded to the panel box via the manufacturer supplied connector. This effectively bonds the the neutrals and grounds in the non service distribution panel (subpanel. Am I wrong about this?

David McCabe

Re: Bonding of nuetrals and grounds.

New postPosted: Wed Apr 21, 2021 4:47 pm
by Jerry Peck - Codeman
bigdog wrote: ... Eaton has those straps that connect both neutral bars ...


There is a metallic strap which goes from one neutral terminal bar to the other neutral terminal bar. Some panels have bent copper bars which are typically located at the top above the breakers; other panels have stamped metal bars which are typically located at the bottom below the breakers.

This connects the neutral bar on one side of the breakers (the terminal bar which the neutral conductor is terminated into) to the terminal bar on the other side of the breakers (this terminal bar does not have the neutral conductor terminated into it. This second terminal bar can be used as either of two options: a) as a neutral terminal bar, in which case the metallic cross-over bonding bar is left in place and serves to bond the two terminal bars together as neutral terminal bars; b) as an equipment grounding terminal bar, in which case the metallic cross-over bonding bar is replaced with a non-metallic (plastic) bar which does not bond the two terminal bars together, in which case the second terminal bar becomes only an equipment grounding bar.

A third choice is frequently found, which is seldom an actual choice given by the manufacturer: c) the metallic bar bonding is removed, no plastic bar is installed in its place.

For many panels (all that I recall having seen) which have this option, the manufacturers state on the label that the cross-over bonding bar is to be replaced with (and gives a part number for the plastic bar). The plastic cross-over bar adds stability to the bottom ends of the two terminal bars.

... and all of the neutrals are connected to them ...


Meaning that there are neutral conductors in each terminal bar, and that the two terminal bars are bonded together with the metallic cross-over bonding bar?

... and it has a separate ground bar for the grounds ...


A separate grounding bar mounted to the enclosure with a screw which bonds the grounding terminal bar to the metal enclosure. This is typically listed on the label as an alternative to using the metallic cross-over bonding bar.

[ ... but the neutral bars are also bonded to the panel box via the manufacturer supplied connector.[/quote]

Correct. But only correct when the panel is used as service equipment. When the panel is used for other than as for service equipment, the neutral terminal bars are left isolated from the enclosure (ground).

This effectively bonds the the neutrals and grounds in the non service distribution panel (subpanel. Am I wrong about this?


Correct. And as a non-service equipment panel, the neutrals are required to be isolated from ground.

I have actually only seen one sub panel up close and personal:
Sub Panel 1.jpg

Sub Panel 2.jpg

Sub Panel 3.jpg

Sub Panel 4.jpg

Sub Panel 5 USS TORSK (SS-423).jpg

Re: Bonding of nuetrals and grounds.

New postPosted: Wed Apr 21, 2021 5:28 pm
by bigdog
HAAAAAHAAAAAAHAAAAAAAAA. Thanks for the pictures of a REAL subpanel!!
After 25 yrs of doing this I still doubt myself thinking how could a licensed electrician make that mistake and how could the all powerful all knowing building inspector miss that........
I'm gonna have to get some good pictures too