Two wire sizes in residential box?

Status
Not open for further replies.
wrobotronic

wrobotronic

Senior Member
Location
Colorado
Hello All,
I have a nail on box for a kitchen counter top recept. The box is the end of the line for one of the two small appliance circuits and fed with #12 on a 20A GFCI recept. I am also using the box as a junction for a 15A lighting circuit, thus two #14 romex's are connected together in this box.

The question would be if this is ok per the NEC. Wire fill in the box seems fine, but didn't know if mixing the two sizes was prohibited.

Thank you as always.
 
wrobotronic said:
Hello All,
I have a nail on box for a kitchen counter top recept. The box is the end of the line for one of the two small appliance circuits and fed with #12 on a 20A GFCI recept. I am also using the box as a junction for a 15A lighting circuit, thus two #14 romex's are connected together in this box.

The question would be if this is ok per the NEC. Wire fill in the box seems fine, but didn't know if mixing the two sizes was prohibited.

Thank you as always.
Click to expand...

Keep in mind the code change for 250.148 when your jurisdiction adopts the 2017 NEC.

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).
 
stevenje said:
Keep in mind the code change for 250.148 when your jurisdiction adopts the 2017 NEC.

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).
Click to expand...

What is that jibberish?
 
stevenje said:
Keep in mind the code change for 250.148 when your jurisdiction adopts the 2017 NEC.

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).
Click to expand...

The "or" part of this has always been confusing for me.

This to me makes it sound as if you can connect the EGC's together within the box and not necessarily to the box.

JAP>
 
to me it should say "and" to the box if it was their intention for us to bond to the box in all these cases.

JAP>
 
To me it seems clear that instead of connecting all the EGCs together directly you can connect them all to the box, indirectly connecting them.
Depending on what is in the box, you may be required to connect at least one of them to the box.
A small remaining ambiguity is whether you can mix the two options, i.e bond one EGC to the box and then connect the other EGCs together and add a pigtail to the box.
 
480sparky said:
Doing so means the box is now a grounding conductor. Is it listed for such a use?
Click to expand...

If it's not, how would they ever allow a device on a raised cover or direct metal to metal contact from a device to the box to act as such?

JAP>
 
GoldDigger said:
To me it seems clear that instead of connecting all the EGCs together directly you can connect them all to the box, indirectly connecting them.
Depending on what is in the box, you may be required to connect at least one of them to the box.
A small remaining ambiguity is whether you can mix the two options, i.e bond one EGC to the box and then connect the other EGCs together and add a pigtail to the box.
Click to expand...

Yea, the part about according to 150.148 A-F is the part where the pigtail to the box part comes in I guess.

JAP>
 
jap said:
If it's not, how would they ever allow a device on a raised cover or direct metal to metal contact from a device to the box to act as such?

JAP>
Click to expand...

A mud ring can only serve the devices mounted to it. A box, with multiple grounds attached to it, would be required to ground any and all of those circuits, even those that don't supply devices at that point.
 
stevenje said:
Keep in mind the code change for 250.148 when your jurisdiction adopts the 2017 NEC.

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).
Click to expand...

Was there really any change of what is intended here? I don't see any changes that would effect what most have been doing in their installations if they were compliant before.

2017 (copied from your post)
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).


2014
Where circuit conductors are spliced within a box, or terminated on equipment within or supported by a box,
any equipment grounding conductor(s) associated with those circuit conductors shall be connected within
the box or to the box with devices suitable for the use in accordance with 250.148(A) through (E)
 
ActionDave said:
I think the NEC is trying to make it clearer that they want all the EGCs in the same box, of any size, from any circuit, tied together. I think it's a stupid rule.
Click to expand...
Actually, in both cases, it seems to me to clearly affect only those EGCs whose associated circuit conductors are spliced or terminated within the box.
The (wire) EGC of a circuit which passes unbroken through the box is not covered by this rule in either cycle.
JMO.

Sent from my XT1585 using Tapatalk
 
Status
Not open for further replies.
Top