I'd like to replace an existing light switch with a new, "smart" light switch as one of three switches in a three-gang box.
Looking in the box, I see three pairs of hot and load wires, and three ground wires, but there is also a bundle of five neutral wires pigtailed together.
I don't understand why there are so many neutral wires, or how I'm supposed to attach the neutral terminus of my switch to this bundle. Do I simply remove one of the five from the pigtail and connect it to the switches' terminus, or do I get a brand new (6th) wire, attach one end to the terminus, and pigtail the other end to the bundle?
I'm in Canada, for what it's worth.
Best Answer
Easy. You have five cables coming into the box
Each load line has a switched hot and a neutral. I would mark the switched hots with colored tape, red, blue, yellow etc.
The switches each connect to an always-hot and a switched-hot. Sometimes installers do clever things to daisy-chain the switches, so there aren't 3 always-hots coming from the switches.
So I would expect 5 always-hots nutted together: supply, onward, and 3 switches.
And 5 neutrals nutted together: supply, onward, and 3 loads.
And of course each switch nutted to a switched-hot, if they have pigtails and are not connected directly.
Now with 3 smart switches, you'll have as many as 8 neutrals. That's too much for a wire nut, especially since smart switches tend to have pigtailed wires smaller than the other wires.
I would get a 6" length of white wire (only white or gray will do) and make a pigtail fo break up that fat wire nut, e.g. Put both supplies, the pigtail, and a couple loads under one large wire nut, then put the other end of the pigtail, remaining loads, and smart switches under another wire nut.
If the wire nuts are >10 years old, replace them. The new ones are much better.