Wiring Configuration -- Impossible ?

[JohnF]

I have 2 ceiling boxes that are wired as follows: a 2 wire power cable (feed) enters Box 1 and a 2 wire cable leaves Box 1 to go to Box 2 which contains another 2 wire that leads to a single pole switch. The light in Box 2 gets its power from Box 1 and can operate off the switch. Box 1 light is always hot so it operates on a pull chain. Is there any way that I can use the existing setup so that the one single pole switch operates both ceiling box lights. Should there have been a 3-wire some place in this mix? Thanks in advance. John

[Matt]

John -

Yep, you need 3 wires between the 2 ceiling boxes; one lead to carry the hot on to the switch via box 2, one lead to carry the switched hot back to the light in box 1, and the third is your neutral.

Matt

[Matt]

Maybe more detail, if ya need it:

Replace the 2 wire cable running between the 2 lights with 3 conductor wire.

In Box 1, tie all your grounds together and secure with wire nut. In Box 1, connect the black (incoming power) to the black wire going out. In Box 1, connect the red wire (from the 3 wire cable) to the hot side of the fixture. In Box 1, connect the incoming white to the outgoing white. Pigtail another wire off this connection, and hook to the neutral side of the fixture.

In Box 2, tie all your grounds together and secure with wire nut. In Box 2, Connect the black (incoming wire from the 3 wire cable) to the black wire which runs to the switch. In Box 2, Connect the white (incoming wire from the 3 wire cable) to the neutral of the fixture. In Box 2, Wrap a piece of black electrical tape around the insulation of the white wire coming from the switch, to act as an indicator that this is a switched hot, and not a neutral. In Box 2, Connect the wire you just labeled in the last step to the red wire going to box 1. Pigtail another wire off of this connection, and connect to the hot side of the fixture.

Also, if any of the fixtures have a grounded outlet in them, make sure you run a ground to the green screw on the fixture.

[Ross Mac]

I appears you need a third wire from what I understand here. Disconnect the black wire from the light fixture on box 1 and run a wire of appropriate gauge to the cold side of the switch or the hot side of the other light/box

2 (black wire again) which will probably be easier. Time for a trip to the attic! You may need the next size up of wire nut. Don't force three wires into a small one.Be careful because sometimes colors can be incorrect and trip a breaker. If you want to run a test on which wire is hot and which is nuetral, connect a meter to the black wire and earth ground (green or bare) and there should be about 115 volts or so. To test for the neutral connect your meter to the white wire and the ground and there should be 0 to a few volts or so. This way you know for sure without tripping or trashing a circuit breaker....good luck on your project....Ross

[JohnF]

Thanks Matt. I may be able to get power into Box 2 without a lot of wall destruction. If so am I right to think that the existing 2 wire that now connects Box 1 and Box 2 could become a switch leg and just get hooked up to the existing switch leg? John

[Matt]

Yes, if you can move the power source to box 2, then you are good to go.

[Matt]

Also, you might check out

you could easily use an X10 solution that would prevent you from having to do any destruction at all. Lemme know if you want some help with this....

[JohnF]

Thanks for the details and help offer. On another project I have a major need of a 3-way light in a room where no work can be done without tearing out 2 walls so this X10 sounds like the deal. Best to all for the input. John

[Jeff Wisnia]

Not impossible, just a little arcane, and sort of suitable for a "Car Talk Puzzler".

But, if you really want to do it without having to run any extra wires, just go here and buy four 34 volt light bulbs, they come in 25, 50, 75 and 100 watt sizes, you'll need all four to be the same wattage.

Wire everything (the 4 bulbs and the switch) in series, running the hot supply through the black wires all the way to the switch, and then come back from the switch through all four bulbs and the white wires to the neutral. Your choice - two bulbs at each location or three in one and one in the other.

Good luck finding which bulb needs replacing when one burns out, but they should last a good while since they'll be running a little undervoltaged.

So much for the folks who said it couldn't be done.

Jeff (And if anyone thinks I'm being serious they need help more than I do.)

Jeff

[Terry]

The basic answer is "Yes there should have been 3 wires between box 2 and box 1. As you have suggested. Can you get a three wire cable between the two boxes or even another two wire plus ground to provide the third wire? In other words the switch wired from box 2 provides a 'switched live' for the light there, and, normally, the only way to get that switched live back to box 1, to control that light as well, is a third wire! There are some 'illegal' and unsafe ways to do it but won't go into that. Unlike Jeff I was going to suggest (and I don't think this would be code or understandable to anyone else except the person who will wire it and is also potentially unsafe. So do not recommend it). Convert the circuit to 230 volt. i.e. make the neutral into the other leg of the 230 volt supply (you are in North America with a 115-0-230 supply, right?) using a double pole breaker. Then wire the two 115 volt lamps in series using the switch connected to box 2 through the first light back through the other light to the other side of the 230 supply. As said it is NOT safe, it is NOT standard and someone including a family member or the next owner could get a lethal

115 (or 230) volt shock just replacing a bulb; EVEN WITH THE SWITCH OFF. Also insurance liability considerations. So don't do it! But I've seen worse in other countries! And I've seen a set up, in North America, where someone used the ground wire as neutral; that's NOT safe don't do it.

[Phisherman]

Run a single wire from box 2 to box 1. This will be the black wire on the other side of the switch that will replace the existing black wire connected to the hot side of lamp on box 1.