Using conductors of different size

[dec]

I've heard many pros and cons about this subject and wanted to hear from you guys for the real story. Here goes.
A home run is pulled for the rec room duplex receptacles using 12/2with ground NM type cable. The circuit is protected via one 20 amp breaker. An overhead combo ceiling fan with light fixture needs to be powerd, so is it permissible to tap off of the receptacle circuit and feed the ceiling fan/light using # 14/2 with ground NM cable?
The argument I've been hearing is that once you start with a particular wire size, it must be continued through out the entire circuit.
The other side says that the # 14 can be mixed in because it is rated for 20 amps. The reasoning being it is supplied via a 20 amp breaker anyway.
Can you shed some light on this ?

 

[pappysparks]

Re: Using conductors of different size

#14 awg wire is rated for 15 amps not 20,you are right if the circuit is on a 20 amp bkr then you use #12 all the way.

 

[don_resqcapt19]

Re: Using conductors of different size

In general #14 must be protected by 15 amp or smaller overcurrent protective device. See 240.4(D).
Don

 

[bthielen]

Re: Using conductors of different size

This topic seems to be coming up quite a bit lately. I have been referencing the NEC since the 1990 code year and I do not recall ever reading that it was allowed to use 14awg on a 20A circuit for residential use. Has there been a time recently where this was allowed and if not, why is this such a common question?

Bob

 

[roger]

Re: Using conductors of different size

It seems there was an explosion of misreading or misinterpretation of 210.19 when "backstab" devices were redesigned to accept no more than #14.

Roger

 

[charlie]

Re: Using conductors of different size

There is nothing wrong with mixing #14 and #12 wire on the same circuit. The only problem is that as soon as the first piece of #14 is included in the circuit, the overcurrent protection must be dropped to 15 amperes, unless specifically permitted in 240.4(E) through (G).

 

[earlydean]

Re: Using conductors of different size

This includes those "pigtails" of #14 wire used on 20 amp circuits to "tap" for 15 amp receptacles. These are not taps, but rather branch circuit wiring, and must be protected by a maximum 15 amp OC device.

 

[cs409]

Re: Using conductors of different size

i see a lot of 20amp circuits with #14 switch legs.

 

[steve66]

Re: Using conductors of different size

It seems to me that the code would allow this for a ceiling fan/light fixture assuming the load is less than 12 amps (80% of 15 amps for a continuous load).

I seem to be the only guy on the other side of the fence here, so what am I missing? Don mentioned 240.4(D). But that refers to 240.4(E) and that refers to 210.19(A)(4). And 210.19(A)(4) reads like it permits #14 taps on a 20A circuit.

Steve

 

[dec]

Re: Using conductors of different size

Looks like I've struck a nerve here.
Thanks for the input !

 

[pierre]

Re: Using conductors of different size

As Don has mentioned, in general these types of taps are not permitted (one example of this being permitted is for certain motor circuits). 210.19(A)(4) Exception No.1(c) does not permit taps of the types mentioned in this thread.

Wiring from a switch to a fixture is not tap conductors, but falls under branch circuit wiring and has to comply with a chapter 3 wiring method.

Pierre

 

[bphgravity]

Re: Using conductors of different size

I interpret the exceptions to 210.19(A)(4) as being specificaly for the conductors that are the connection points to most luminaires and other fixtures. The conductors from a ceiling fan or other light fixture are never the size of the branch circuit conductors, but are sized as tap conductors for the individual fixtures.

It goes hand in hand with the allowances of 240.5(B). Most lamp cords and fixture wires are sized by this section and are protected by branch-circuit overcurrent protection.

It is has always been my opinion that the wording of the branch circuit section and all referenced within are confusiong and easily miisunderstood. Table 210.24 for example should simply be removed as it only serves by distorting the actual text sections.