Need advice on how to wire everything properly. There are two wire harnesses coming into the junction box:
- H1: black(!), white, ground – comes from the fuse box
- H2: black, white, ground, red(switch) – beginning of a circuit, extending into 2 rooms on the same floor.
I am adding an electrical outlet therefore i have black wire nut with 3 black cables, white wire nut with 3 white cables, red wire nut for the switch wire and ground cables are under the screws.
If I were to add a light fixture, obviously black is going under the same wire nut with red(H2), ground goes under a screw but I am not sure where the white one goes.
From my understanding, it can go under the same white wire nut that will result in 4 wires on a same wire nut BUT i could be wrong. Still reading material but not able to put everything together when it comes to the neutral wiring.
Best Answer
There is a new rule that requires receptacles in bathrooms be on dedicated circuits, in one of two arrangements (pick one):
Your setup is grandfathered since it predates this rule. However, you would break the grandfathering if you do too much work.
As such, if you have an existing receptacle in the bathroom, I would extend off its junction box for another receptacle in the same bathroom. If this circuit does not power any bathroom receptacles and your new receptacle won't be in the bathroom, then you can put "hot" with the existing blacks and "neutral" with the existing whites.
Otherwise you are not grandfathered and you need to pull a new circuit.
If you want to put another light off that same switch, it can either be powered off the existing lamp location, or this box. In this box, neutral goes to the neutral bundle, and switched-hot goes to the black-red wire nut.
Watch out for box cram/fill. If that's a 2-gang box, that's already pretty busy. Officially, count all wires except grounds as 1 each. Count all grounds together as 1. Count all cable clamps together as 1. Now count 2 for every switch or receptacle. Multiply by 2.0 if your wires are #14, or 2.25 if #12. You need that many cubic inches, and look inside the box for a stamped number stating cubic inches.
In your box I see 9 conductors + 1 (grounds) + 1 (cable clamps): 11. That is 22 cubic inches for #14 wire, or 24.75 cubic inches for #12.