# Sub panel bonding **URL:** \ **Category:** Electrical Inspections\ **Created:** [June 14, 2015, 1:54am UTC](https://forum.nachi.org/t/sub-panel-bonding/97483 "2015-06-14T01:54:50Z")\ **Posts on this page:** 14\ **Page:** 1
**Author:** ![mbruchs](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/mbruchs/32/180995_2.png) [@mbruchs](https://forum.nachi.org/u/mbruchs)\ **Post date:** [June 14, 2015, 1:54am UTC](https://forum.nachi.org/t/sub-panel-bonding/97483/1 "2015-06-14T01:54:50Z")
Can the ground bar in a sub panel be grounded back to the main electric panel or must it be bonded to the sub panel box? First picture yellow conductor is attached to ground bar. Second picture the yellow conductor is attached to neutral/ground bar in the main panel. ![IMG_0977.jpg](https://global.discourse-cdn.com/internachi/original/3X/b/9/b9339ef5c7daba3f533398a03deba13013f1368f.jpeg) ![IMG_0975.jpg](https://global.discourse-cdn.com/internachi/original/3X/b/b/bbeb58c15c8ad0b175168574e4fcb4ad79bd0bf3.jpeg) ---
**Author:** ![jpope](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/jpope/32/59425_2.png) [@jpope](https://forum.nachi.org/u/jpope)\ **Post date:** [June 14, 2015, 2:50am UTC](https://forum.nachi.org/t/sub-panel-bonding/97483/2 "2015-06-14T02:50:21Z")
The grounding terminal must be bonded to the cabinet at all electrical panels, whether it’s a service panel or “sub” panel. The neutral conductors must remain isolated from the equipment grounding conductors at all but the service panel. ---
**Author:** ![mbruchs](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/mbruchs/32/180995_2.png) [@mbruchs](https://forum.nachi.org/u/mbruchs)\ **Post date:** [June 14, 2015, 3:39am UTC](https://forum.nachi.org/t/sub-panel-bonding/97483/3 "2015-06-14T03:39:29Z")
Thanks Jeff, The neutrals were isolated in the sub panel. The grounding terminal was not. ---
**Author:** ![rmeier2](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/rmeier2/32/59909_2.png) [@rmeier2](https://forum.nachi.org/u/rmeier2)\ **Post date:** [June 14, 2015, 11:23am UTC](https://forum.nachi.org/t/sub-panel-bonding/97483/4 "2015-06-14T11:23:07Z")
Is the yellow conductor run in with the feeder conductors? If so it’s an equipment grounding conductor and needs to green, green with yellow stripe, or bare. ---
**Author:** ![jpope](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/jpope/32/59425_2.png) [@jpope](https://forum.nachi.org/u/jpope)\ **Post date:** [June 14, 2015, 1:54pm UTC](https://forum.nachi.org/t/sub-panel-bonding/97483/5 "2015-06-14T13:54:12Z")
> [@mbruchs](#): > > Thanks Jeff, > > The neutrals were isolated in the sub panel. The grounding terminal was not. If that yellow conductor is connected to both the neutral terminal and the grounding terminal, then the neutral terminal is not isolated. Subsequently, if the grounding terminal is bonded to the enclosure, the neutral terminal is also bonded to the enclosure. ---
**Author:** ![ccurrins](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/ccurrins/32/225758_2.png) [@ccurrins](https://forum.nachi.org/u/ccurrins)\ **Post date:** [June 14, 2015, 2:27pm UTC](https://forum.nachi.org/t/sub-panel-bonding/97483/6 "2015-06-14T14:27:59Z")
> [@jpope](#): > > The grounding terminal must be bonded to the cabinet at all electrical panels, whether it’s a service panel or “sub” panel. > > The neutral conductors must remain isolated from the equipment grounding conductors at all but the service panel. What if it’s only a 3-wire feed? ---
**Author:** ![rmeier2](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/rmeier2/32/59909_2.png) [@rmeier2](https://forum.nachi.org/u/rmeier2)\ **Post date:** [June 14, 2015, 2:33pm UTC](https://forum.nachi.org/t/sub-panel-bonding/97483/7 "2015-06-14T14:33:34Z")
According to the OP the photo’s are of two different panels. One where the yellow EGC originates and one where it terminates. ---
**Author:** ![ccurrins](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/ccurrins/32/225758_2.png) [@ccurrins](https://forum.nachi.org/u/ccurrins)\ **Post date:** [June 14, 2015, 3:56pm UTC](https://forum.nachi.org/t/sub-panel-bonding/97483/8 "2015-06-14T15:56:28Z")
> [@Robert\_Meier](#): > > According to the OP the photo’s are of two different panels. One where the yellow EGC originates and one where it terminates. My question is “when” there is only a 3-wire feed (HHN) to a remote distribution panel does this still apply? > [@](#): > > The neutral conductors must remain isolated from the equipment grounding conductors at all but the service panel. ---
**Author:** ![rmeier2](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/rmeier2/32/59909_2.png) [@rmeier2](https://forum.nachi.org/u/rmeier2)\ **Post date:** [June 14, 2015, 4:03pm UTC](https://forum.nachi.org/t/sub-panel-bonding/97483/9 "2015-06-14T16:03:30Z")
A feeder within the same structure must have an EGC along with the feeder conductors so a 3-wire feeder (H-H-N) is not permitted unless it’s a separate structure and installed under an older version of the NEC. ---
**Author:** ![ccurrins](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/ccurrins/32/225758_2.png) [@ccurrins](https://forum.nachi.org/u/ccurrins)\ **Post date:** [June 14, 2015, 4:14pm UTC](https://forum.nachi.org/t/sub-panel-bonding/97483/10 "2015-06-14T16:14:56Z")
> [@Robert\_Meier](#): > > A feeder within the same structure must have an EGC along with the feeder conductors so a 3-wire feeder (H-H-N) is not permitted unless it’s a separate structure and installed under an older version of the NEC. So when the service disconnect is at the pole, is the house considered a separate structure? If so, when older NEC versions allowed a 3-wire feeder were the neutrals still required to be isolated from the grounds at the panel? ---
**Author:** ![Jim\_Port](https://avatars.discourse-cdn.com/v4/letter/j/bc8723/32.png) [@Jim\_Port](https://forum.nachi.org/u/Jim_Port)\ **Post date:** [June 14, 2015, 4:44pm UTC](https://forum.nachi.org/t/sub-panel-bonding/97483/11 "2015-06-14T16:44:39Z")
In older codes a three wire feeder to a detached building was allowed. The neutral was again bonded to the grounds. You could have no metallic path between buildings. ---
**Author:** ![jpope](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/jpope/32/59425_2.png) [@jpope](https://forum.nachi.org/u/jpope)\ **Post date:** [June 14, 2015, 11:04pm UTC](https://forum.nachi.org/t/sub-panel-bonding/97483/12 "2015-06-14T23:04:12Z")
> [@Robert\_Meier](#): > > According to the OP the photo’s are of two different panels. One where the yellow EGC originates and one where it terminates. I didn’t catch that initially… ---
**Author:** ![ccurrins](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/ccurrins/32/225758_2.png) [@ccurrins](https://forum.nachi.org/u/ccurrins)\ **Post date:** [June 15, 2015, 3:02pm UTC](https://forum.nachi.org/t/sub-panel-bonding/97483/13 "2015-06-15T15:02:51Z")
> [@Jim\_Port](#): > > In older codes a three wire feeder to a detached building was allowed. The neutral was again bonded to the grounds. You could have no metallic path between buildings. And the neutrals and grounds were also bonded to the panel, preferably with a ground rod at the building, correct? Thanks Jim. ---
**Author:** ![Jim\_Port](https://avatars.discourse-cdn.com/v4/letter/j/bc8723/32.png) [@Jim\_Port](https://forum.nachi.org/u/Jim_Port)\ **Post date:** [June 15, 2015, 3:24pm UTC](https://forum.nachi.org/t/sub-panel-bonding/97483/14 "2015-06-15T15:24:45Z")
If the detached building is served by a feeder, not a single circuit, a grounding electrode is required. The detached building panel was treated like a service and the bond was established.