I am putting electrical service to a outdoor shed and a chicken coop. I had outside service to a pool. The pool is no longer there. the wire to the pool was 12/2. I have wired the coop with 14/2 outside wire and I just dug a 18 foot ditch min of 18" deep. I was going to put the wires through the conduit, and I saw the wire coming from the house was 12/2. there is no way I can change that wire at the circuit box. can I use the 14/2 or do I need to change the shed and coop to 12/2?
It's perfectly fine to use the 12/2 wire, but if it's connected to 14/2, the circuit breaker needs to be 15 amp, not 20 amp, (due to the wire size of the 14 ga wire) and should also be GFCI (not due to the wire size, due to the location/use being outside)