SOLVED. Thanks.

Thread Starter

Tonyr1084

Joined Sep 24, 2015
5,976
I have a hallway I want to light when you walk into it. Bought a motion detector light switch. It has four wires. Hot (black), Neutral (white), Switched (red) and Ground(green). Inside the box there is only one black wire and one white wire. I KNOW the wiring is "Interrupt". Which means hot goes to the lamp. From the lamp it goes to a switch. From the switch it goes back to the box and joins with the neutral. There is no ground. And though technically it's a neutral switched side, is there any way I can use this detector?
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be80be

Joined Jul 5, 2008
2,051
Your maybe wrong years ago wire came with only 2 wires and it was common to use the white tied to hot the black going to load and the neutal on the load return side. New codes dont let you do that now days.
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Reloadron

Joined Jan 15, 2015
5,934
Normally when done that way a strip of black tape would be wrapped on the white wire which should be the switched to the light. The problem is older house wiring does not run neutral through the switch gang box. You need a neutral for your motion sensor switch to work. Not that it does you any good now but the newer revisions to the NEC require a neutral through the switch gang box for the very reason you have for needing a neutral. What you likely have is what be80be just posted. If you have a neutral running through the switch gang box you are fine but if not and only the hot passes through you will need a neutral.

Ron
 

Thread Starter

Tonyr1084

Joined Sep 24, 2015
5,976
Well, I opened the wall and put a hole through the sill plate and ran a new wire down into the basement. The two wires from the switch box going up to the light fixture will run hot and neutral and not be in any way connected to the rest of the lines that run through the ceiling box. While in there I disconnected the transformer for the old style doorbell system. It's been on for years without being used.

Tomorrow I'm getting a bigger gang box. There's no way I can fit the wires, wire nuts and the PIR in that tiny metal electrical box. Once I have that part done I'll be tying into the power down stairs, power that runs the washroom lights, freezer and the bathroom lights. Not overloading the system at all.

One thing that amazes me is the 12 gauge wiring throughout the house. Would have been cheaper to go with 14 gauge and a breaker at 15 amps instead of the 20 amp breakers there now. Oh well. Hard as hell stuffing all that stuff into a box. But it's doable.

Actually, be80be the hot in the ceiling fixture was tied to the white wire running down into the switch. Black came back up to the other leg of the fixture.
 
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