Mixing 12 & 14 gauge wire in a circuit.

[jar546]

We often see DIY people doing their own work and mixing 14 & 12 on the same circuit and we have to tell them they must be on a 15A breaker.

I have come across some union electricians who run 14 from switches to fixtures but have them on a 20A breaker which IS a problem. I was told that they have been taught this for years because they are using the tap rule. OK, really?

Anyway, the first subject is a bit touchy because it makes it difficult to perform an inspection when all of the wires coming into the panel are 12 but many of the circuits have 14 in them too.

There is nothing against code mixing wire size for these circuits as long as the OCPD matches the smallest wire. We ask them to mark the wires with tags in the panel so that in the future and for final inspection, we know what is what. I wish it was in the code to require marking the maximum OCPD or stating the smallest wire size in the panel ON the wire (probably with non-conductive, not flammable tags). This has been a sore subject and no one has given us a hard time about marking them, even though it is not code and we simply tell them that's what we would like to see now that you have mixed 12 n 14.

Of course commercial is another story due to voltage drop, etc. but I posted this in residential.

 

[raider1]

Jeff,

Just a bit of info you might find interesting.

As you probably already know I sit on CMP 10. CMP 10 covers Article 240. During the 2014 code hearings a proposal to require marking conductors as you have mentioned was purposed and passed the proposal stage. During the comment stage the proposal failed.

Here is the proposal and the comments.

_______________________________________________________________________________________________10-18 Log #1548 NEC-P10

_______________________________________________________________________________________________

David Clements, International Association of Electrical Inspectors

Revise text to read as follows:

Add the following sentence to the end of 240.4: Where circuit conductors are increased in size for any reason, such as

voltage drop or de-rating, they shall be marked or tagged with: Maximum circuit ampacity xxx amps.

When an installer uses larger conductors for a circuit because of voltage drop or de-rating factors

there is no indication for follow up installers or owners of the intended circuit size. Persons could look at the conductor

size and install larger overcurrent protection based on the size of the conductor and inadvertently cause the circuit to be

over loaded.

Add new section after Section 240.4 as follows:

240.11 Where circuit conductors are increased in size for voltage drop or

derating purposes, the conductors shall be marked or tagged at the point where the conductor(s) receive their supply

with the maximum level of overcurrent protection. The identification means shall be suitable for the environment.

The intent of the submitter is met with the action to create a new section, which increases usability.

The exception was added by the panel to exempt installations where documentation of such installation detail is readily

available.

The proposal was accepted in principal and modified at the proposal stage. Notice that it was the IAEI who submitted the proposal.

Here is the ballot final at the comment stage.

10-8Eligible To Vote:12 Affirmative: 11 Negative: 1 Abstain: 0 Not Returned: 0

240.4

(Log # 1012 )

Negative

Kauer, R.

There is an issue when conductors are increased in size and the reason for the increase is not readily apparent due to the conductors

being concealed. It makes it very difficult to determine the correct overcurrent protective device for future repairs and replacements when these

conditions exist. Labeling of the conductors, when oversized, with the maximum overcurrent protective device size will help future repairs and

replacements be made in a safe and code compliant manner

Notice that at the comment stage all the other panel members except me and Robert Kauer voted to reject the change.

Chris

 

[TimNY]

Well, look at who filed the comment.

The vote says Kauer was the only person to support changing the code at the comment stage?

 

[raider1]

Well, look at who filed the comment.The vote says Kauer was the only person to support changing the code at the comment stage?

Yes, Robert Kauer was the only voting member of Panel 10 to support the change at the comment stage. I also supported the change but am not a voting member but sit as the alternate to Robert Kauer.

Chris

 

[jar546]

Chris, Thanks for the information and no, I did not know you were on the CMP and don't know your full name either. Very interesting as this truly is a problem at the inspection stage because we see it during rough but not final and it is final when the breakers are installed and we cant do anything about it although we do with no resistance.

 

[raider1]

This proposal will most likely be resubmitted for the 2017 NEC.

Chris

 

[michaelj]

This is why our county has a a local amendment that minimum 12 ga. wire to be used.

 

[fatboy]

Throughout the house?

 

[TimNY]

Yes, Robert Kauer was the only voting member of Panel 10 to support the change at the comment stage. I also supported the change but am not a voting member but sit as the alternate to Robert Kauer.Chris

I only mention it because you said both and he voted, but there was only 1 vote supporting the change.

The reasoning Mr. Holt used is interesting in that I agree on premise, but the code is full of similar requirements. He did make his point quite colorfully. I also liked the quip from the panel member about "unqualified people in the panel". How many electricians do you know that match that description?

Tim

 

[raider1]

I only mention it because you said both and he voted, but there was only 1 vote supporting the change.The reasoning Mr. Holt used is interesting in that I agree on premise, but the code is full of similar requirements. He did make his point quite colorfully. I also liked the quip from the panel member about "unqualified people in the panel". How many electricians do you know that match that description?

Tim

Yes it was a very lively discussion to say the least.

Mike did have a good point, so the IAEI will go back to the drawing board and see if we can come up with a better proposal that may not be as broad as this one was.

Chris

 

[Uncle Bob]

This is why our county has a a local amendment that minimum 12 ga. wire to be used.

. At the AHJ I worked at last in Texas; we also amended the code to only allow 12 and not 14. It sure made things more simple during electric rough inspections.