National Electrical Installation Standards

Standards as High as Your Own

 
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Monday, October 21, 2019

Question:

 

I recently built a house for a client. My electrician ran 12/2 romex cable from the breaker box to the switch of a bedroom. From the switch, he ran 14/2 romex cable to the outlets and switches. He used a 15 amp breaker for this circuit. I have read many places online where it states this is allowed. The client of the home hired an electrician himself and stated that the house has to be rewired because all circuits must use the same gauge wire. Can you point me to the section in the code where it states one way or another which is correct? Thank you.  

Ernesto Jimenez
A

Answer:

Hey Ernesto thanks for your question. The Word “Romex” is a registered trademark of Southwire Company. We have been asked to point that out, the correct term is Nonmetallic Sheathed Cable Type NM.

The NEC does not require that all conductors in a circuit length be the same size. Sometimes larger conductors are used to deal with voltage drop concerns. Conductors must be protected as stated in 240.4. In your example the 12 AWG conductors are protected below their ampacity and the 14 AWG conductors are protected based on 240.4(D). That is allowed.

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