Reply To: Miscellaneous Electric Tips

Pashuteh Yid-

First of all, you did exactly the right thing by getting a getting a pro when you found the wiring more complicated than you were comfortable with.

The explanation below is based on the assumption that you have a “switch before” arrangement – the electricity goes to the switch boxes before it goes to the fixture. It also assumes there are no additional splices in the switch boxes.

The setup you described as I understand it is three switch boxes ganged together, with each switch controlling one or more fixtures.

There should be four cables in the box – one hot/neutral going into the box, and three going to the fixtures.

The switches/fixtures are wired as parallel circuits like so:

Hot

|    |   |

s1   s2  s3

|    |   |

f1   f2  f3

|    |   |

Neutral

The way this is accomplished is:

1) Three pigtails (short pieces of wire) are spliced to the hot wire in the switch box. A larger wire nut may be needed for this splice – some large wire nuts look a bit like a deflated balloon. Additionally, care must be taken to ensure all wires in the splice have good connections.

(Your previous setup probably had the three dimmer leads spliced directly to the hot.)

[An alternate arrangement that uses jumpers from switch to switch by using the screw terminals and connector holes in back of the switches won’t be discussed here.]

2) Each pigtail’s other end is connected to a switch’s screw terminal.

3) The other screw terminal is connected to the black wire of a cable going to a fixture.

4) The white wires returning from the fixtures are spliced directly to the neutral in the switch box.

I also seemed to see one group of multiple white wires all twisted together…

This sounds like “4)”, above.

…with some copper wire wrapped around all of them seemingly to hold them together.

I’d have to see this to understand, but it doesn’t sound right.

Also, when there are multiple switches for one room (many lights) in one box, is there always a bunch of spaghetti connecting them together, rather than one cable per switch?

It may look that way, because of the need to connect each switch to the one hot coming into the box, as well as the fact that the neutrals from the fixtures end up spliced together.

How are multiple lights in a room normally handled?

Generally, as I described above.

I assume they are on one circuit, but I turned off the main before beginning work.

They are almost definitely all on one breaker. You can just flip breakers until all the lights you will be working on are off. (It is uncommon but not unheard of to have circuits from more than one breaker in the same box, so you should make sure all the lights go off.)

I understand they are probably in parallel, but my question is in practice, do you always see these kinds of splices in a box, or are there dedicated wires for each area of the ceiling connected to dedicated switches in the box

The cable from the switch to the fixture will be dedicated.

Your arrangement is probably a single two-conductor cable going from each switch to a fixture box. There will probably be a splice in the fixture box to an additional cable if more than one fixture is on the line. (“Probably” and not “definitely” because there can be two separate cables to two separate fixture boxes with the splice after the switch in the switch box.)

If you have outlets or other fixtures running from your switch boxes it can be more complicated. I omitted possible three-conductor cable arrangements from the explanation above because I don’t think it’s likely you have such a setup (it would be likelier with two switches).

Overloaded boxes are not uncommon (more connections and cables than code allows), which can certainly give it a “spaghetti” appearance (not that that’s what your box has).

Switch boxes are sold in differing depths – deeper is always better if you have room for it, to allow more room for wires, splices, and bulkier switches (timers, dimmers).