multiple wire gauges in box

[nolabama]

i cant find a reference forbiding multiple wire gauges in a j box together - can i put #12 and #14 in a box together? application is residential kitchen and also bathrooms - lighting circut and gfci in same box - i seperate the nuetral and the ground when i do this - i was told i cannot do this but no code reference was sited

 

[infinity]

i cant find a reference forbiding multiple wire gauges in a j box together - can i put #12 and #14 in a box together?

Whoever said that you cannot do this is incorrect. You will not find this in the NEC.

 

[masterinbama]

No code issue I can think of. As long as you OCPD is properly sized. Maybe someone thinks you can't do a box fill calculation using the #'s stamped on most residential boxes for different sizes. I had a residential guy try to tell me that you could not use 15A switches on a 20 A circuit because #12 wouldn't go in the backstabs.

 

[electricguy61]

i cant find a reference forbiding multiple wire gauges in a j box together - can i put #12 and #14 in a box together? application is residential kitchen and also bathrooms - lighting circut and gfci in same box - i seperate the nuetral and the ground when i do this - i was told i cannot do this but no code reference was sited

I believe all grounds need to be connected.

 

[nolabama]

thank you and have a blessed christmas - we have an inspector that "doesnt like it" imo some inspectors dont like taffy but i shouldnt have to change the way i wire a bathroom or kitchen if its code compliant

 

[nolabama]

all grounds connected ok no problem will do

 

[nakulak]

210.24 (2005) -see the table. taps in branch ckts as indicated here are specifically allowed

 

[augie47]

- i seperate the nuetral and the ground when i do this - i

no problem as far a mixing conductors. you might want to look at 250.148 in regard to your equipment grounds.

 

[macmikeman]

thank you and have a blessed christmas - we have an inspector that "doesnt like it" imo some inspectors dont like taffy but i shouldnt have to change the way i wire a bathroom or kitchen if its code compliant

Well spoken words noalabama.

 

[nolabama]

i dont quite follow the connection of the grounded - this is multiple circuts - i dont mix the grounded because of gfci protection - is this wrong also ?

 

[jeremysterling]

If I may assume a little:

Not only can they be in the same box together, you can terminate them together if the smaller (for example, the #14) conductor's ampacity is not exceeded by the overcurrent protection. This would be legal by the NEC.

Case in point: Light fixture has a #14/2c switch leg. At the switch box, there is #12/2c homerun. The #14 white is wirenutted to the #12 white. The #14 black (switchleg) is on one screw(terminal) of the switch and the #12 black (homerun) is on the other screw. At the panel, the #12 black is terminated to a 15 amp breaker.

The install described above is NEC legal, but not widely used for many reasons. Typically, this is only done if #12 is the only wire available, (e.g. because you used up all the #14 on the switchleg)

Two reasons against:

1) #12 is more expensive

2) #12 is typically used for voltage drop and in that case the entire ckt is #12 including the switch leg, so if someone else terminates the panel and sees the #12, they might assume that the entire circuit is #12 and install a 20 amp bkr, which could not protect the #14 switchleg like our above example.

Reason #2 may be why you were told this is illegal. Just a guess.

 

[480sparky]

I sure hope there's no prohibition against having mixed wire sizes.

I shudder to think I'll need a panel for 15a circuits, another for 20a circuits, yet another for 30a circuits, one for the range......

Jeez. How would you feed all those panels if you can't mix #12 with a #whatever to power it?

 

[nolabama]

I sure hope there's no prohibition against having mixed wire sizes.

I shudder to think I'll need a panel for 15a circuits, another for 20a circuits, yet another for 30a circuits, one for the range......

Jeez. How would you feed all those panels if you can't mix #12 with a #whatever to power it?

thanks a bunch guys - i feel stupid at times were i work without the skills nessacary to talk sense into some people - i apperciate the ability to get a straight answer here

 

[Dennis Alwon]

thank you and have a blessed christmas - we have an inspector that "doesnt like it" imo some inspectors dont like taffy but i shouldnt have to change the way i wire a bathroom or kitchen if its code compliant

I believe all grounds need to be connected.

i dont quite follow the connection of the grounded - this is multiple circuts - i dont mix the grounded because of gfci protection - is this wrong also ?

I think electricguy is talking about the grounding conductor not the grounded conductor. You do not want the grounded conductor of multiple circuits tied together regardless of GFCI protection or not.

 

[nolabama]

no problem as far a mixing conductors. you might want to look at 250.148 in regard to your equipment grounds.

the grounded was refering to this quote

i read 250.148

soo...

grounding together
grounded seperate
hots lowest gauge = ocpd rating

got it:smile:

 

[frenchelectrican]

the grounded was refering to this quote

i read 250.148

soo...

grounding together
grounded seperate
hots lowest gauge = ocpd rating

got it:smile:

That is the very simple answer and that the way we been doing for long time { It work both USA and European system the excat same way }

Merci,Marc

 

[infinity]

the grounded was refering to this quote

i read 250.148

soo...

grounding together
grounded seperate
hots lowest gauge = ocpd rating

got it:smile:

Nice explanation 'bama. :smile:

 

[don_resqcapt19]

i cant find a reference forbiding multiple wire gauges in a j box together - can i put #12 and #14 in a box together? application is residential kitchen and also bathrooms - lighting circut and gfci in same box - i seperate the nuetral and the ground when i do this - i was told i cannot do this but no code reference was sited

Many of the circuits for residential kitchens and bathrooms are required to be 20 amp circuits and you are not permitted to use #14 on a 20 amp circuit.;

 

[MASTERFRANK]

2 gang box next to kitchen sink, 20 amp receptacle circuit in 12. 15 amp circuit for light over sink 14 guage. seperate neutrals all grounds tied together with one 14 and one 12 pigtailed out.

 

[ptonsparky]

...
Two reasons against:

1) #12 is more expensive

2) #12 is typically used for voltage drop and in that case the entire ckt is #12 including the switch leg, so if someone else terminates the panel and sees the #12, they might assume that the entire circuit is #12 and install a 20 amp bkr, which could not protect the #14 switchleg like our above example.

Reason #2 may be why you were told this is illegal. Just a guess.

Art 250.122(B) NEC 2008 should also be considered when changing wire sizes mid stream.