3

I recently learned about a new species of breaker panel known as the "plug-on-neutral" design. All the major load center manufacturers seem to be making these now. The idea is to provide a neutral bar at a fixed distance on each side of the bus bars, so specially-designed AFCI or GFCI breakers can plug directly onto the bus bar and the neutral bar without requiring a pigtail connection. Here's a picture from a catalog:

enter image description here

The extra-long breakers in the middle are the AFCI ones which snap directly onto the neutral bar. Very clever!

But I'm confused about how this panel could be configured as a subpanel. In the picture the two neutral bars are clearly connected (somehow, where is the bonding strap?) and they are connecting both neutrals and grounds to both. In a subpanel, the neutrals and grounds must be separated.

Does this mean one of those bars must be separated from the neutral somehow, in which case the fancy plug-on breakers would be limited to one side of the panel? Or can they both be isolated and a separate ground bar installed (how?)

It seems like it would be a waste if only one side could take advantage of the plug-on AFCI/GFCI, since almost every room requires one or the other now.

Improve this question

3 Answers 3

Reset to default
3

You'd have to remove the bonding jumper, and install a separate grounding bar.

Notice in this image, there are clearly separate grounding bars installed.

enter image description here

Improve this answer
4
  • Thanks - do you know if these panels typically come with the extra ground bar or do you have to buy a kit? I'm having trouble making sense of some of these product catalogs.
    – friedo
    Jul 21, 2015 at 16:26
  • Not sure. I'd guess you have to buy it separately, but have no idea.
    – Tester101
    Jul 21, 2015 at 16:44
  • It varies. Some suppliers include them, others make you buy a kit they sell. Some of them electrically attach to the panel frame using the mounting screws, and via those screws to the other ground bar, if there's two. I'm not a fan. I prefer hardwiring a ground wire those places. Grounds are one place you are allowed to parallel.
    – Harper - Reinstate Monica
    Dec 18, 2018 at 0:21
  • Isn't this answer wrong? If this PON panel is going to be used as a sub-panel, then the bonding jumper (or strap whatever it is called) should not be removed. Instead, the bonded bus will serve as neutral and a separate grounding bar bonded to chassis will act as an isolated ground. I recommend accepting Ehryk's answer below to avoid any confusion for future readers of this question.
    – cryptic0
    Jul 8, 2021 at 17:13
3

To use this as a subpanel you would have to buy a seperate ground block and grounding lug with enough spaces for your circuits or maybe two that could be combined with #6 or #8 bare copper. Then your bare stranded ground would connect to this new ground block and your neutral wire would connect to the lug where the bare stranded ground was connected before. If you remove the bonding strap then you loose neutral on breaker function for one side of the panel thus rendering any AFCI breakers on the affected side nonfunction for Arc Fault.

Improve this answer
1
  • 1
    Hello, and welcome to Home Improvement. Good answer: keep 'em coming!
    – Daniel Griscom
    Jan 6, 2019 at 1:39
3

Here is the location of the bonding strap that links the two neutral bars. It could likely be removed if so desired, but those two should stay linked and be tied with that strap to neutral so that the plug on neutral AFCI and GFCI breakers can operate properly.

To use it as a sub-panel, you would add a grounding bar tied into the metal casing (where as you can see by the plastic insulators, these neutral bars are not bonded to the chassis/ground).

Bonding Strap Location

Improve this answer

Not the answer you're looking for? Browse other questions tagged or ask your own question.