Do all EGC's need to be tied?

[FionaZuppa]

Does NEC require all EGC's in a box to be tied together even if the far end of one EGC is tied back to the panel bus bar?

Example (resi all plastic):
2-gang w/ one 3way switch and one duplex receptacle with ckt for receptacle.
Across the room is a 1-gang 3way switch with it's own ckt for power (lights).

So, you see how this goes, one 14-3 home-runs between the two boxes, the EGC for that 3way wire is tied to ckt EGC in the 1-gang box.

Does the 14-3 EGC in the 2-gang need to be tied to the EGC of the ckt that feeds the receptacle?

The 2-gang 14-3 EGC would land on the yoke of the switch, but I don't see where NEC requires the "all in box" must be tied together.

 

[Dennis Alwon]

This is the best we have and it has been argued often on the forum. My answer is yes all the equipment grounding conductor's must be spliced together

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.

 

[FionaZuppa]

But in my case each box only has one ckt. I don't have multiple ckts feeding equip or device (switch, recept, etc) in either box.

Isn't 250.148 just saying, if I bring a ckt to a box that's 10ft away from the equip-A, I need to extend that ckt (splice) it the rest of that 10ft to the equip, thus I must have continuity of the EGC (for that ckt) in the box, by either tying the EGC's together or connecting them to the box (metal).

Now, I bring ckt #2 to same box, and the equip for that is located 15ft to the left of equip-A, I need to splice the ckt #2 EGC (in the box) down to the equip-B, for continuity, "ckt continuity".

But does 250.148 say I have to tie EGC ckt #1 to EGC ckt #2?

 

[jaggedben]

.

But does 250.148 say I have to tie EGC ckt #1 to EGC ckt #2?

Yes. Either directly to each other or to the box, assuming it's metal. It says 'or' not 'and'.

You could:
- Wirenut all the different EGC ends together, including to a pigtail that is bonded to the box.
- Install a ground bar to the box and land all the EGCs on it
- land all the EGCs to the box with appropriate lugs or screws
- other similar things or combos

You can not:
Pass the EGC for circuit #2 through the box without bonding it to the box, if you spliced circuit #2 in the box.

BTW in your described scenario there is no need to bring an EGC with circuit #2 if it comes from the same place through the same conduit as circuit #1 and isn't bigger.

 

[Tulsa Electrician]

Yes. Either directly to each other or to the box, assuming it's metal. It says 'or' not 'and'.

You could:
- Wirenut all the different EGC ends together, including to a pigtail that is bonded to the box.
- Install a ground bar to the box and land all the EGCs on it
- land all the EGCs to the box with appropriate lugs or screws
- other similar things or combos

You can not:
Pass the EGC for circuit #2 through the box without bonding it to the box, if you spliced circuit #2 in the box.

BTW in your described scenario there is no need to bring an EGC with circuit #2 if it comes from the same place through the same conduit as circuit #1 and isn't bigger.

Pretty sure he is using NM .

 

[FionaZuppa]

You can not:
Pass the EGC for circuit #2 through the box without bonding it to the box, if you spliced circuit #2 in the box.

BTW in your described scenario there is no need to bring an EGC with circuit #2 if it comes from the same place through the same conduit as circuit #1 and isn't bigger.

All NM-B and plastic boxes.
The ckt being used for 3way light switches does neither, it does not pass through the box nor is it spliced in the box, the wire fully terminates in the 2-gang box and lands all 4 wires (14-3) on the switch itself.

I guess I am missing the point of tying all EGC wires together when they are from different ckt's.

Think about two 2-gang boxes 20ft away, ckt #1 feeds box 1 and box 2, the ckt EGC carries from one box to the other, but then you drop in a loopback 14-3 for connecting two 3way switches. When you bring back the 14-3 to the other box the ckt EGC is already there, spliced, and carries all the way back again. So what's the point of taking that 14-3 end EGC and tying it again, forming a EGC loop (literally two EGC's) between the two boxes?

 

[LarryFine]

I guess I am missing the point of tying all EGC wires together when they are from different ckt's.

So what's the point of taking that 14-3 end EGC and tying it again, forming a EGC loop (literally two EGC's) between the two boxes?

Lower impedance EGC pathway, and there's no good reason not to. EGCs don't have ground-loop issues.

 

[FionaZuppa]

Lower impedance EGC pathway, and there's no good reason not to. EGCs don't have ground-loop issues.

Where does NEC say that?

I know reason why more copper means lower ohms.

No good reason? If the EGC is like any other that runs down a set of ckt CCC's (NM-B as example), and the device yoke/case is connected to that EGC, an EGC is there.

I can perhaps name one reason/example not to. It's two less wires to twist into a wire nut (wire egc and then a needed pigtail), might perhaps need a bigger wire nut to accommodate, thus more box fill.

Perhaps another reason. If say you tied EGC's from three ckt's and a fault from ckt-1 fries EGC wire of ckt-3, or EGC in ckt-3 gets hot enough to burn the CCC's of ckt-3 wire, that's good and desired?

What has less ohms to the yoke, a direct wire, or a wire nutted pigtail?

 

[ActionDave]

.....What has less ohms to the yoke, a direct wire, or a wire nutted pigtail?

What would be the reason to worry about it?

 

[LarryFine]

I can perhaps name one reason/example not to. It's two less wires to twist into a wire nut (wire egc and then a needed pigtail), might perhaps need a bigger wire nut to accommodate, thus more box fill.

Silly reason, in my opinion. If anything, separate EGC joints take up more room than one larger one.

Perhaps another reason. If say you tied EGC's from three ckt's and a fault from ckt-1 fries EGC wire of ckt-3, or EGC in ckt-3 gets hot enough to burn the CCC's of ckt-3 wire, that's good and desired?

Why would that happen? Ckt 1's EGC should trip the breaker long before any heat is developed.

What has less ohms to the yoke, a direct wire, or a wire nutted pigtail?

They should be equally low if made up well. Again, direct faults should be short-duration events.

 

[FionaZuppa]

Silly reason, in my opinion. If anything, separate EGC joints take up more room than one larger one.


Why would that happen? Ckt 1's EGC should trip the breaker long before any heat is developed.


They should be equally low if made up well.

It's not multiple EGC joints. One wire (NM-B cable) the EGC is directly attached to the yoke of a switch, no joint.

You mean Ckt 1 OCPD should trip with fault amps now running across multiple EGC's back to panel. I dunno, "should" is a ominous word given the way some electrical work is done.

Equally low? A very small contact point (area) will have low ohms too, until you pass amps through it. The concept still applies to "made up well" joints.

If the switch yoke has ckt-1 EGC on it, then I still not getting why it needs or should be tied to ckt-2 EGC. One EGC path is all that's required, yes? I was looking for NEC words that make it a requirement when multi ckt's are in same box, or even perhaps an EGC that loops back to same box of a single ckt.

 

[LarryFine]

Equally low? A very small contact point (area) will have low ohms too, until you pass amps through it. The concept still applies to "made up well" joints.

Then how can you trust any joint, splice, or connection? Should every receptacle be individually home-run?

 

[don_resqcapt19]

But in my case each box only has one ckt. I don't have multiple ckts feeding equip or device (switch, recept, etc) in either box.

Isn't 250.148 just saying, if I bring a ckt to a box that's 10ft away from the equip-A, I need to extend that ckt (splice) it the rest of that 10ft to the equip, thus I must have continuity of the EGC (for that ckt) in the box, by either tying the EGC's together or connecting them to the box (metal).

Now, I bring ckt #2 to same box, and the equip for that is located 15ft to the left of equip-A, I need to splice the ckt #2 EGC (in the box) down to the equip-B, for continuity, "ckt continuity".

But does 250.148 say I have to tie EGC ckt #1 to EGC ckt #2?

If both circuits are either terminated or spliced in the box, they must be connected to each other and in the case of a metallic box, to the box. Individually connecting each EGC to a metal box, does both jobs.

 

[FionaZuppa]

If both circuits are either terminated or spliced in the box, they must be connected to each other and in the case of a metallic box, to the box. Individually connecting each EGC to a metal box, does both jobs.

So, does it says that though? I not reading it to say that.


"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,................."


The end of the 3way (14-3) is not spliced in the box, nor is the box used for "equipment".

 

[FionaZuppa]

"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,................."

Quoted for reference.

Does the last part in blue, define the 3way switch as "equipment"? The switch itself is supported by the box (switch is screwed to the box), and, the ckt does terminate on the switch. Is that the actual meaning of 250.148?

A switch seems to be an "outlet", not "equipment". Equipment consumes power, an outlet does not.

From NEC definitions:

Outlet. A point on the wiring system at which current is
taken to supply utilization equipment

Utilization Equipment. Equipment that utilizes electric energy
for electronic, electromechanical, chemical, heating,
lighting, or similar purposes.

 

[FionaZuppa]

If connecting all EGC's was it, why the 250.148 simply not say:
(less some exceptions)

"Unless the ckt is passthrough (not spliced or terminated in the box), then all EGC's shall be bonded together. When box is metallic, the box itself must also be bonded to EGC"

 

[don_resqcapt19]

Quoted for reference.

Does the last part in blue, define the 3way switch as "equipment"? The switch itself is supported by the box (switch is screwed to the box), and, the ckt does terminate on the switch. Is that the actual meaning of 250.148?

A switch seems to be an "outlet", not "equipment". Equipment consumes power, an outlet does not.

From NEC definitions:

Outlet. A point on the wiring system at which current is
taken to supply utilization equipment

Utilization Equipment. Equipment that utilizes electric energy
for electronic, electromechanical, chemical, heating,
lighting, or similar purposes.

It says "equipment" and not "utilization equipment. Equipment is defined very broadly and includes pretty much everything that an electrician installs. In your case the conductors terminate on a switch, which is a device, and devices are equipment.

Equipment.
A general term, including fittings, devices, appliances, luminaires, apparatus, machinery, and the like used as a part of, or in connection with, an electrical installation.

A switch is not an outlet.

 

[FionaZuppa]

So, the 250.148 does seem to be convoluted in words.
To me, it definitely reads in context of "ckt egc's".

And with metal boxes and yokes that are metal with EGC screw, don't they all bond even if the EGC wires themselves are not twisted together or tied directly to box?

I had short discussion about it with AHJ inspector, he too said 250.148 was a bit confusing, and said the minimum to do is per ckt but did recommend all, but not a fail as long as the 3way egc had continuity back to panel bus.

 

[FionaZuppa]

A switch is not an outlet.

Perhaps not the switch (yoke) itself. But take as example a hardwired thingy that has a wire coming out (no box / no splice on thingy), and there's a box near it, in that box is thingy wire, a switch, and end of a branch ckt. That box is the outlet. I would call that a "switch outlet". NEC does have "lighting outlet" in definitions, but that's different type of setup, etc.

 

[don_resqcapt19]

Perhaps not the switch (yoke) itself. But take as example a hardwired thingy that has a wire coming out (no box / no splice on thingy), and there's a box near it, in that box is thingy wire, a switch, and end of a branch ckt. That box is the outlet. I would call that a "switch outlet". NEC does have "lighting outlet" in definitions, but that's different type of setup, etc.

A switch is NEVER an outlet...the outlet is where the wire from the load side of the switch connects to the actual load. Also a box is never an outlet...the outlet is aways at the end of a conductor, the end that connects to the load.