Art. 240

Status
Not open for further replies.
O

OLDMAN2

Member
Can 14 awg and 12 awg be intermixed on branch circuits provided the o.c.p.d. Matches the smaller wire size? (general purpose branch circuit) voltage drop is not an issue
 
240.4 (D) (3) and (5) LEAD YOU TO BELIEVE THAT YOU CANNOT INTERMIX WIRE SIZES ON A BRANCH CIRCUIT OR SWITCH LEGS WHICH IS HOW I'VE ALWAYS DONE IT, BUT HAVE ALWAYS BEEN A BIT CONFUSED.
 
You can mix & match wire sizes as much as you want. Just protect the entire circuit based on the lowest ampacity conductor.

I've installed lot lighting (480V) on 2-pole 20a breakers. I run #12 from the breaker to the contactor, then run something substantially larger such as 6 or 4 out to the pole bases. #10s get run up each pole. As long as the breaker protects the 'weakest link', life is good as far as the NEC is concerned.:wink:
 
480sparky said:
You can mix & match wire sizes as much as you want. Just protect the entire circuit based on the lowest ampacity conductor.

I've installed lot lighting (480V) on 2-pole 20a breakers. I run #12 from the breaker to the contactor, then run something substantially larger such as 6 or 4 out to the pole bases. #10s get run up each pole. As long as the breaker protects the 'weakest link', life is good as far as the NEC is concerned.:wink:
Click to expand...

I agree. :smile:
 
I agree with what the others have said.

As 480sparky pointed out, it is common to upsize wire for voltage drop. This is fine provided that the OCPD is sized to protect the smallest conductor.

Chris
 
raider1 said:
I agree with what the others have said.

As 480sparky pointed out, it is common to upsize wire for voltage drop. This is fine provided that the OCPD is sized to protect the smallest conductor.

Chris
Click to expand...

When I was inspecting for a company years ago, if I encountered the situation where the circuit would originate in #12 and have #14 downstream, I would ask the electrician to tag the wire in the panel to indicate not to protect at more than 15 amps. Never had a problem with that. :)
 
wbalsam1 said:
When I was inspecting for a company years ago, if I encountered the situation where the circuit would originate in #12 and have #14 downstream, I would ask the electrician to tag the wire in the panel to indicate not to protect at more than 15 amps. Never had a problem with that. :)
Click to expand...

As long as you just suggested it and not required it I would be fine with it.

Chris
 
wbalsam1 said:
When I was inspecting for a company years ago, if I encountered the situation where the circuit would originate in #12 and have #14 downstream, I would ask the electrician to tag the wire in the panel to indicate not to protect at more than 15 amps. Never had a problem with that. :)
Click to expand...

Good idea, but unfortunately, not an NEC requirement (yet..... hint hint).

I typically do the same thing as SOP.

Whenever I do a resi upgrade, I always put the existing general-purpose branch circuits on a 15a breaker regardless of whether they're 14, 12 (or even the occasional 10) and ignore whatever size breaker was installed originally. I've never had a call-back for a 15a tripping.
 
raider1 said:
As long as you just suggested it and not required it I would be fine with it.

Chris
Click to expand...

That's all I would do. And I would also explain that he did not have to since it was not required by code. In this way I was able to have cooperation with no problems. You get more bees with honey than you do with vinegar. :smile:
 
wbalsam1 said:
That's all I would do. And I would also explain that he did not have to since it was not required by code. In this way I was able to have cooperation with no problems. You get more bees with honey than you do with vinegar. :smile:
Click to expand...

I agree, I have been known to make suggestions in the past as well.

Chris
 
Status
Not open for further replies.
Top