Bonding #14 to #12 in plastic box

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Is it a violation not to bond the #14 EGC to the #12 EGC?

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Sea Nile

Sea Nile

Senior Member
Location
Georgia
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Electrician
I came across this today. Multi gang boxes that have both 14 AWG and 12 AWG.

I always bonded All EGC together in boxes regardless of size. Whoever roughed in this house felt the need to keep the #14 and #12 separate.

I don't think it's a violation, because everything still has an effective ground fault path back to the source.

I've never done a poll before so here goes.
Is it a violation to not bond the #14 grounding wire to the #12 grounding wire?IMG_20220823_094145391~2.jpgIMG_20220823_110111123~4.jpg
 
It is not a violation to bond the #14 and #12 together. I read the section to mean that they must be bonded together. Many disagree with that reading of 250.148
 
Dennis Alwon said:
It is not a violation to bond the #14 and #12 together. I read the section to mean that they must be bonded together. Many disagree with that reading of 250.148
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I never thought it was a violation to bond them, but I was curious if people thought it was a violation to not bond them.

Edit:. Ok I reread what you wrote.. you interpret it to mean they must be bonded
 
Dennis Alwon said:
Yes but not everyone agrees with that interpretation. I have always tied all the equipment grounding conductor together regardless of their size.
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250.148 seems pretty clear to me in what it requires: take every circuit whose conductors are spliced or terminated in a box, take all their EGCs, and bond them together and/or to the (metallic) box.

Cheers, Wayne
 
letgomywago said:
Not a violation to do and in a metal box it would be required to have them all bonded to the box. It is common in nonmetalic boxes to separate into associated grounds like by circuit in multigang boxes.
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Perhaps common but a violation of 250.148. It's not ambiguous.

Cheers, Wayne
 
wwhitney said:
Perhaps common but a violation of 250.148. It's not ambiguous.

Cheers, Wayne
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Not ambiguous to you or I but others read it as all equipment grounding conductor of that circuit should be tied together. Suppose there is a box that had 2 circuits- one #12 wire and the other 14 wire however the #14 wire is the only wire spliced.
 
Dennis Alwon said:
Not ambiguous to you or I but others read it as all equipment grounding conductor of that circuit should be tied together. Suppose there is a box that had 2 circuits- one #12 wire and the other 14 wire however the #14 wire is the only wire spliced.
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If it's a plastic box, do you ever run a cable through it that isn't spliced or terminated? That would be very odd, you could just route the cable around the box.

Say it's a metal box with 4 conduits going through, one pair with a #12 circuit coming and out, unspliced and unterminated; and another pair with a #14 circuit being spliced in the box. Then only the #14 circuit's EGC need to be connected to the box, the #12 EGC can pass through.

But that's not what the OP is about. It would be about a plastic box, and both circuits are spliced in the box, but the EGCs are connected #14 to #14, and #12 to #12, with the two sets remaining unconnected. That violates 250.148:

" . . . all equipment grounding conductor(s) associated with any of those circuit conductors shall be connected within the box . . ."

They all need to be connected together.

Cheers, Wayne
 
wwhitney said:
If it's a plastic box, do you ever run a cable through it that isn't spliced or terminated? That would be very odd, you could just route the cable around the box.

Say it's a metal box with 4 conduits going through, one pair with a #12 circuit coming and out, unspliced and unterminated; and another pair with a #14 circuit being spliced in the box. Then only the #14 circuit's EGC need to be connected to the box, the #12 EGC can pass through.

But that's not what the OP is about. It would be about a plastic box, and both circuits are spliced in the box, but the EGCs are connected #14 to #14, and #12 to #12, with the two sets remaining unconnected. That violates 250.148:

" . . . all equipment grounding conductor(s) associated with any of those circuit conductors shall be connected within the box . . ."

They all need to be connected together.

Cheers, Wayne
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I agree but as I have stated others have argued this here before. Maybe one of them will jump in. I think Bob Badger may have been one of them but not certain
 
Dennis Alwon said:
I agree but as I have stated others have argued this here before. Maybe one of them will jump in. I think Bob Badger may have been one of them but not certain
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OK, the language I quoted above was from 2017 and 2020, the 2014 language was different. The change was from Public Input No. 1331-NFPA 70-2014, with the substantiation:

"This section is frequently misunderstood to mean that where multiple circuits are present in a box the EGS's for each circuit are to be connected together but not connected to the EGC's of other circuits that are present. This change clarifies that all of the EGC's present in the box are required to be connected together regardless of the circuit they are associated with."

The panel accepted the change with the statement:

"The revised text clarifies that all of the EGC's present in the box are required to be connected together regardless of the circuit they are associated with."

So perhaps it was debatable before the 2017 NEC, but both the language and the intent are clear now.

Cheers, Wayne
 
wwhitney said:
The revised text clarifies that all of the EGC's present in the box are required to be connected together regardless of the circuit they are associated with.
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I wish they had just said that in plain English. All those brains on the panel and they can't seem to decrypt the code.
 
I've always found this to be stupid. If I have a riser box with multiple runs of larger conductors say 750's with #4/0 EGC's that are all being spliced through what purpose does connecting all of the EGC's together serve? If there are no splices they're not connected so why should the presence of splices change anything?
 
infinity said:
I've always found this to be stupid. If I have a riser box with multiple runs of larger conductors say 750's with #4/0 EGC's that are all being spliced through what purpose does connecting all of the EGC's together serve? If there are no splices they're not connected so why should the presence of splices change anything?
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More connections = lower impedance (more parallel paths). But if the circuit wouldn't otherwise be spliced, introducing an extra splice is a burden. So the requirement is only when the circuit is already being spliced.

Cheers, Wayne
 
wwhitney said:
More connections = lower impedance (more parallel paths). But if the circuit wouldn't otherwise be spliced, introducing an extra splice is a burden. So the requirement is only when the circuit is already being spliced.

Cheers, Wayne
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But it makes no sense because electrically the impedance isn't an issue when they're not spliced together. If the raceway is an EGC the wire type EGC isn't even required so to me the entire argument that splicing everything together is needed to lower the impedance is bogus.
 
infinity said:
the entire argument that splicing everything together is needed to lower the impedance is bogus.
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Needed? No. But if the wires are getting spliced anyway, seems like splicing everything together is a free option, and it increases redundancy. What's the downside?

Cheers, Wayne
 
wwhitney said:
and it increases redundancy. What's the downside?

Cheers, Wayne
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Believe it or not around 2015 I had an engineer ( I didn't believe he was then and still don't) tell me that tying EGC's of multiple circuits together should not be done. I told him that in the case of EGC's the more parallel paths even if not the same characteristics was a good thing and in fact couldn't be avoided in a building with metallic piping and metal framing. He stood there with a serious face and told me it created ground loops and he did not want the noise and other problems they caused in his building. o_O

To top it off it was a medical facility and when I pointed out 517.13 He said those areas were designed around ground loops 😁
 
I always understood that all EGC's need to tie together, and to the box/enclosure if it is metallic. Any changes more recently must been to help clarify something that people were interpreting as an exemption for connecting all them together?

I will admit to occasionally not tying them all together with multiple circuits multigang NM cable boxes like what is in OP, particularly if there is a 15 and 20 amp circuit in that box, but have always understood per code wording they should be tied together.
 
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