Interpretation of 210.19(A)(4) Exception No.1(a).

[Greentagger]

In regards to the usage of #14 for a switch leg on a 20A circuit, would 210.19(A)(4) Exception No.1 apply? Or would 240.4(D)(3) apply? Help me see the light please. Thanks.

 

[infinity]

This is not covered in 240.4(D) under the clause "Unless specifically permitted in 240.4(E) or (G)" that allows this. As you stated this is clear in 240.4(D)(3) that 15 amps is the max for #14 conductors in this installation.

 

[augie47]

Note, even if applicable, the max length would be 18"

 

[kwired]

If the switch loop is actually an art 725 class 1 control circuit it possibly can have more than the conductor ampacity for overcurrent protection, but it generally would be supplying something like a contactor coil and not the actual utilization equipment load.

For typical general lighting circuits where you are directly switching the lighting load you can not use 15 amp switch loop conductors on 20 amp circuits though many seem to think it is ok and has been done quite often over the years.

 

[don_resqcapt19]

There is a fine line where fixture wire starts and the protection is permitted to be per 240.5(B)(2) and where the branch circuit conductor ends. How is a fixture wire extended from a switch to a single luminaire different from 18 AWG fixture wire extended 50' from a junction box to a single luminaire?