Do I have to tie all grounds together?

[JoeNorm]

When a 20 amp outlet circuit comes into the same 2 gang box as a 15 amp lighting circuit do I have to tie all the grounds in that box together? Or can I keep grounds separate to their respective circuits?

 

[Dennis Alwon]

You must tie them together

 

[Dennis Alwon]

Here is the section

250.148 Continuity and Attachment of Equipment Grounding
Conductors to Boxes. If circuit conductors are spliced within
a box or terminated on equipment within or supported by a
box, all equipment grounding conductor(s) associated with any
of those circuit conductors shall be connected within the box
or to the box with devices suitable for the use in accordance
with 250.8 and 250.148(A) through (E).
Exception: The equipment grounding conductor permitted in
250.146(D) shall not be required to be connected to the other equipment
grounding conductors or to the box.

 

[LarryFine]

There is no downside. Imagine it's conduit similarly routed.

 

[infinity]

I say if they spiced straight thorough then no need to tie them all together. That's a poorly written code section.

 

[jaggedben]

I say if they spiced straight thorough then no need to tie them all together. That's a poorly written code section.

You mean if any are run straight through without splicing? I agree that would be permitted, although such an EGC would never be required.

 

[infinity]

What I'm saying is that if you had two 12/2 cable and two 14/2 cables there is no reason that all four EGC need to be spliced together. If the box is metallic the largest EGC would connect to the box.

 

[Knuckle Dragger]

If the box were metallic I would ground both circuits to the box.
I don't always tie them together, if I do I may pigtail off of one circuit to the other. Sometimes it more manageable that way.

 

[ActionDave]

What I'm saying is that if you had two 12/2 cable and two 14/2 cables there is no reason that all four EGC need to be spliced together. If the box is metallic the largest EGC would connect to the box.

That is the way I do it, although based on discussions here where the ROPs about this section were shown I think the intent is that all the EGCs be spliced together. I don't care though, it's a silly requirement and the section is badly written enough that I'm unlikely to change.

 

[Dennis Alwon]

It seems clear to me that all the conductors that are spliced should be connected together. In Trevors example, I would disagree with him and imo the #12 and #14 equipment grounding conductor's should be tied together.

I understand that the wording is fuzzy to some but I believe the intent is as I stated. I could be wrong

 

[ggunn]

Why wouldn't you want to bond them? It seems to me that doing so decreases the resistance of the EGC for both circuits and therefore increases the fault clearing ability for both of them.

 

[480sparky]

More to the point: What is to be gained by not tying them together?

 

[LarryFine]

As I said in post #4, if you had separate circuits in separate conduits enter the same box, all of the "EGCs" would be connected.

I suppose one could argue that interconnecting EGCs places small conductors in parallel, which is contraindicated in the NEC.

 

[480sparky]

As I said in post #4, if you had separate circuits in separate conduits enter the same box, all of the "EGCs" would be connected.

I suppose one could argue that interconnecting EGCs places small conductors in parallel, which is contraindicated in the NEC.

Where is paralleling small grounds contradicted (contraindicated?) in the NEC?

 

[JoeNorm]

There is not necessarily anything "gained" by not tying them together. But when you have a large number of grounds, especially mixed sized (12 and 14) it's nice to be able to manage them seperately, I might even say I'm less likely to end up with a loose ground within a big gob of wires if I do it this way(less wires to have to get in one wire nut).

I am not arguing one way or the other, mainly just curious if it was mandatory to always do so.

 

[480sparky]

There is not necessarily anything "gained" by not tying them together. But when you have a large number of grounds, especially mixed sized (12 and 14) it's nice to be able to manage them seperately, I might even say I'm less likely to end up with a loose ground within a big gob of wires if I do it this way(less wires to have to get in one wire nut).

I am not arguing one way or the other, mainly just curious if it was mandatory to always do so.

I had cases of so many grounds I can't fit them all under one wire nut. But I don't see an issue of bundling 3 or 4 of them under one nut, then taking another one the same size as the largest in the group, and using it to tie to another wire nut with the rest of the grounds.

 

[Knuckle Dragger]

I had cases of so many grounds I can't fit them all under one wire nut. But I don't see an issue of bundling 3 or 4 of them under one nut, then taking another one the same size as the largest in the group, and using it to tie to another wire nut with the rest of the grounds.

Yup.

 

[ActionDave]

Why wouldn't you want to bond them? It seems to me that doing so decreases the resistance of the EGC for both circuits and therefore increases the fault clearing ability for both of them.

What you gain in fault clearing ability is about the same as flushing an eyedropper full of iodine down the toilet to help the city with sewage treatment.

What you loose is some management of the wires in your junction box.

 

[LarryFine]

Where is paralleling small grounds contradicted (contraindicated?) in the NEC?

I didn't say it was a good argument.

 

[JoeNorm]

So from what I am reading there is not a clear answer? Does that mean I can choose? I am not concerned with fault clearing ability as I believe it is negligible. The code language did not seem absolute as far as I can tell. Correct me if I am wrong.