View Full Version : Need to rewire a series of lights
nyogha
Apr 11, 2009, 11:16 AM
I live in a very old house with a maze of wires running all over the place. I'm in the process of simplifying. I'll keep this as brief as possible. I want the power to run to the light, not the switch like all the diagrams I've come across say to do. So, from the breaker to the light, then from that box one line to run down to the switch and another line to run to the kitchen light. And can I do this with 2 conductor wire? (Not sure if that's the right terminology... I mean wire with a black, white and ground.)
stanfortyman
Apr 11, 2009, 11:26 AM
You can legally and safely run a 2-wire switch loop from the light down to the switch, but then you will not have a neutral to continue power on to the kitchen light switch.
So the answer is no, you cannot do it with only 2-wire cable.
hkstroud
Apr 12, 2009, 08:22 PM
Stan
Please note.
(I would assume another line is another line from the light box to the kitchen light box)
breaker to the light, then from that box one line to run down to the switch and another line to run to the kitchen light.
stanfortyman
Apr 12, 2009, 08:25 PM
Maybe I did read it wrong. I took it that the kitchen light will be switched separately.
If not then he would still need 3-wire between the first light and the switch.
ohb0b
Apr 12, 2009, 08:41 PM
I think you are talking about an un-switched light. The light is on whenever the circuit breaker is on? Other than why on earth would you want to do this, I have a couple other questions, which I will make assumptions about.
If so, you wire it just as you would a receptacle. You are using "two wire cable," so I assume you mean Type NM (AKA "Romex") This is a black wire, and a white wire, and a bare wire, covered by an overall plastic covering (jacket).
The black wire is called the "hot" the white wire is technically called the "groundED" conductor, but most folks refer to it as the "Neutral. A bare or green wire is the "groundING" wire.
I am also assuming you have only one circuit breaker panel in the house (there are no sub-panels, just the one connected to the electric service)
At the light socket, connect the black wire to the brass screw, and the white wire to the silver screw, and the bare wire to the green screw. If you are using metal boxes, you also need to connect the grounding wire to the box.
At the circuit breaker box (the Service Panel) connect the white wire and the bare wire to the Nuetral buss. (If you are wiring a sub-panel, these wires go to separate busses) and the black wire to the circuit breaker.
Safety: Make sure the circuit breaker is OFF before connecting the wire. To be really safe, turn off the Main breraker. NOTE: Even with the Main breaker off, the wires coming from the electric company into the service panel are still live.
If you are using a 20 amp breaker, all circuit wires need to be No. 12 AWG. If you are using a 15 amp breaker, you can install No. 14 AWG and save a few bucks.
hkstroud
Apr 12, 2009, 09:48 PM
Sorry Stan,
Just reading the question as poster wants to know if 2-wire cable can be used to feed the fixtures, (with a switch leg) instead of feeding the switch as is shown in some do-it-you-self wiring diagram.
ohb0b
Apr 12, 2009, 09:51 PM
I live in a very old house with a maze of wires running all over the place. I'm in the process of simplifying. I'll keep this as brief as possible. I want the power to run to the light, not the switch like all the diagrams I've come across say to do. So, from the breaker to the light, then from that box one line to run down to the switch and another line to run to the kitchen light. And can I do this with 2 conductor wire? (Not sure if that's the right terminology... I mean wire with a black, white and ground.)
OK.. re-read the question! What I think you are saying is the "home run" from the service panel is the to the box with the light (Box A). From that box, you want to go to a switch (Box B), then to another light (Box C). The switch will control the light, and the circuit will continue in Box C.
You will need a 3 conductor cable to run from box A to B, (Black, White, Red, and Ground) and a 2 conductor cable from box B to C. (Black, White, Ground)
Note: The bare grounding wire is not included when you specify number of wires in a cable. You tell the supply house you want 12-2G or 14-3G cable, etc.
At box A:
1. Connect the white wires from the home run and the cable going to box B together, and "pigtail" them to the white screw on the light fixture.
2. Connect the red wire to the brass screw on the fixture.
3. Connect the two black wires together.
At box B:
1. Connect the black wires from box A and C together, and pigtail them to one screw on the switch.
2. Connect the red wire to the other screw on the switch.
3. Connect the white wires from box A and C together.
At box C:
You have one unswitched hot wire (Black) and one neutral wire. (white) You can continue the circuit from there.
If you are not going to continue the circuit from box B:
At box A:
1. Connect the black wires from the home run and box B together.
2. Connect the white wire from the home run to the silver screw on the light fixture.
3. Mark the white wire from box B with a wrap of electrical tape, and connect it to the brass screw on the light fixture.
At box B:
Connect the white and black wires from Box A to the screws on the switch.
As usual, connect the grounding wires to the green terminals on the devices, and also to any metal boxes.
Hope this helps!
nyogha
Apr 12, 2009, 10:41 PM
Sorry Stan,
Just reading the question as poster wants to know if 2-wire cable can be used to feed the fixtures, (with a switch leg) instead of feeding the switch as is shown in some do-it-you-self wiring diagram.
Is there anything wrong with this diagram? I'd like to use this solution if I can. I'd prefer to use 2 wire cable because I already dealt with the kitchen light/switch a couple of months ago.(I went to replace just the kitchen light fixture and found some melted wire nuts and other surprises) The 12-2G running from the laundry room light to the kitchen light doesn't need to be replaced, but I need to run new wire from the breaker to the laundry room light and to the switch.
hkstroud
Apr 13, 2009, 05:28 AM
Is there anything wrong with this diagram?
I assume that your question is for Stan, however I assure you that this is a perfectly legal, usual, and most often used method of wiring. Nothing wrong with the diagram (unless I made some dumb error drawing it.)
Stratmando
Apr 13, 2009, 06:27 AM
HK's drawing looks good, and most efficient.
nyogha
Apr 13, 2009, 07:19 AM
I assume that your question is for Stan,
Nope, it was for anyone who could provide a strong argument why your method would be wrong. Thanks for the help and thanks for everyone's input.
ohb0b
Apr 13, 2009, 09:47 AM
HK's drawing looks good, and most efficient.
Exactly. The lights will work as drawn. Just make sure to mark the white "switch legs" with a wrap of electrical tape so not to confuse them with neutrals.