neutral wire question

[zapdafish]

previous owners installed a grow light controlled by a wall switch in a room for african violets. I've started an indoor herb garden (legal....rosemary, basil, etc.) and keep forgetting to turn on the light. I've been looking at programmable wall timer switches and lots of them require a neutral wire.

Just curious what are the odds a 10 year old house was wired that way? I'll be checking this weekend.

Looking into home automation and it seems just about all of them require a neutral wire so also wondering how hard it is to backfill a house with neutral wires where needed.

Thanks

 

[KenOfCary]

I assume rather the the white neutral wire (black is hot) you really mean ground wires (copper or green). I can't imagine not having neutral or return wiring even in older homes but can imagine not having grounds. Sometimes the metal conduit was substituted for ground.

I'm no expert on electrical wiring so I won't comment further on retrofitting / safety / etc.

 

[MarkE]

I have seen quite a few wall switches that only had the hot wires going through the box. That was mostly in older homes. I had to run a neutral wire to several boxes in our old house (built in 1975) in New Hampshire in order to add some X10 type switches.

Our house here, built in 2008 and my shop, built in 2010, have neutral wires connected with wire nuts in every switch box. Hopefully yours will be the same.

 

[redknife]

You’ll have neutral wires in the switch junction box. The hassle can be where there are multiple lines in the junction box with the neutrals tied together in a big bunch and hot wire only through the switch. You have to make sure you keep track of the bystander wires as you unbundle the neutrals, add a pigtail for your switch, rebundle and separate the outgoing neutral to attach to the switch. Easiest scenario is if the switch is in a single gang and at the end of the circuit.

 

[zapdafish]

oh so based on wires that I've seen, black = hot, white = neutral, green = ground?

For some reason when looking at the schematic that came with the switch I thought there was a 4th wire that was considered neutral. lol.

 

[Phil S]

Many times power is run to the light junction box and then a hot is sent down to a switch and back up to the light. There is no need for a neutral in the switch box. This is common practice. Adding a neutral would be difficult at best

 

[Jeremy Scuteri]

Phil is correct about the "end of line switch" re-purposing the neutral as a hot wire (in a way, similar in concept to what people do with 220v receptacles - no need for a neutral, but two 'hots' are needed). I think switch locations now require a neutral, but I'm not 100% sure. Open up the wall switch and take a look, it should be pretty easy to do.

Is the grow light connected to an outlet that is controlled by a wall switch or is the grow light hard wired to the wall switch? If it is an switch controlled outlet, then you could use something like a WEMO switch and just get rid of the wall switch.