I searched around here and a few other places but didn't really find an answer to my question. I apologize if I am posting something that was already posted. We are putting on a deck with a covered roof and I want the ability to put in a few different switches inside the house so that we can control the exterior lighting.
Inside the house I have a PVC box which has integrated clamps as well as a 1/2 KO for conduit. Rather than make three separate UF-B runs from the interior I want to simplify things, cut down on the wire fill as well as make less stripping of the UF-B by running THHN in 1/2" PVC conduit from the switch box inside out the exterior wall up to the fan box under the roof. I got a deep fan rated box so using that as a junction won't be a problem. As it's deemed a damp location I will run UF-B from the fan box to the other desired areas, that isn't my question.
Within the conduit I plan on running 3 different colored hot THHN wires (not green nor white) in the conduit as well as the common (white) and ground (green). Many years ago an electrician told me that it was okay to use one common wire in a conduit run as long as all of the other wires were attached to the same circuit but I wanted to check it before running all the wire. I want to point out that this is all on the same breaker and isn't looking to share a common wire among different circuits. So is what the electrician told me before still valid and I won't have a problem using that same common wire for all three switches? I think this is okay as even if all threes lights were on at once as long as the load of the circuit is 15amp or less it would be acceptable, thoughts?
Switches inside will control:
Fan under roof
Lights under the roof
Lights for the back yard mounted on the roof support posts
Inside the house I have a PVC box which has integrated clamps as well as a 1/2 KO for conduit. Rather than make three separate UF-B runs from the interior I want to simplify things, cut down on the wire fill as well as make less stripping of the UF-B by running THHN in 1/2" PVC conduit from the switch box inside out the exterior wall up to the fan box under the roof. I got a deep fan rated box so using that as a junction won't be a problem. As it's deemed a damp location I will run UF-B from the fan box to the other desired areas, that isn't my question.
Within the conduit I plan on running 3 different colored hot THHN wires (not green nor white) in the conduit as well as the common (white) and ground (green). Many years ago an electrician told me that it was okay to use one common wire in a conduit run as long as all of the other wires were attached to the same circuit but I wanted to check it before running all the wire. I want to point out that this is all on the same breaker and isn't looking to share a common wire among different circuits. So is what the electrician told me before still valid and I won't have a problem using that same common wire for all three switches? I think this is okay as even if all threes lights were on at once as long as the load of the circuit is 15amp or less it would be acceptable, thoughts?
Switches inside will control:
Fan under roof
Lights under the roof
Lights for the back yard mounted on the roof support posts


