I am extending a lighting and outlet circuit in a basement. The current setup has the following characteristics
- 15 amp. circuit breaker (200 amp service)
- 4 existing lighting fixtures using CFL bulbs (~ 20 W each)
- 1 existing double duplex outlet box (no regular appliance in use)
- 14/2 and 14/3 NM cabling (lighting switched, outlets not) throughout
- less than 100 ft of cabling so far
I plan on adding three lighting fixtures (for LED spots, less than 20W each) and one duplex outlet. I will tap off one of the existing boxes to get both a switched and a constant hot line. Additional cabling will be less than 30 ft.
Is there any reason I cannot use 12/2 and 12/3 NM cabling for this project (I happen to have some on hand)?
Is there any practical benefit (e.g., less voltage drop in this small section of line)?
Is there any disadvantage in doing so, other than higher cost of cabling and the slightly harder handling of thicker wires?
If the cabling were concealed, would the presence of a 12 gauge wire in an outlet box or fixture convey something to an electrician or future DIYer that is misleading based on the existence of unseen 14 gauge wiring upstream?
Best Answer
The OP has a great reason for using 12 ga. wire. He already has some on hand, so using it is cheaper than going to get new 14 ga. wire. It's perfectly safe to use it. Don't worry about confusing future workers. If they want to add something to the circuit, they will have to go turn off the circuit breaker first, and then they will see they are working with a 15 amp circuit. Then, if they have any brains / experience at all, they will see that there is 14 gauge wire hooked up to that 15 amp circuit breaker, so they will know not to upgrade it to a 20 amp breaker. Your plan is perfectly fine.