Neutral Wire Required

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  #1  
Old 10-09-14, 12:02 AM
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Neutral Wire Required

OK, so I think I may have been confused.

I've been adding a lot of home automation stuff to my home recently. It's an older home built in the 50s. Bear with me, because I know enough about wiring to replace a light switch or receptacle without shorting and to do it properly.. and I could add a simple wire to a junction to a receptacle, but I don't know the terminology at all.

Many receptacles and switches that work with home automation kits say 'Neutral Wire Required'. I was under the impression that this meant that it needs Black, Red, and White wires (as well as Ground) to function properly. However, as I've been trying to learn and reading various things it seems White is always Neutral. Have I been wrong? If I have a switch that has Black and White, does that have a Neutral and would work with these types of switches?
 
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Old 10-09-14, 12:34 AM
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If I have a switch that has Black and White, does that have a Neutral
No. You have a white wire that was not remarked black (or red or any color but green or gray) as required by code. It is a switch loop.

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Old 10-09-14, 01:06 AM
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OK, that makes more sense. Previous owner(s) lose 50 points for not marking things correctly.

So switches that need a neutral just need to be able to complete a circuit to be powered all the time separate from the light. I think what confused me is that I've seen ZWave receptacles that say 'Neutral wire required'.. but that doesn't make sense.
 
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Old 10-09-14, 01:40 AM
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The electronics that work the switch need the neutral to function. Some older types of added function switches like timers pulled power through the light they were hooked up to but that only works for incandescent light bulbs. (To put it another way they connected to the neutral at the light through the filament in the bulb.)

In some rare cases there is a third way. If the electronic use less than 5 milliamps the ground can be used as a neutral. However this is now becoming a moot point with new codes requiring a neutral in all switch boxes that aren't connected by conduit even if the neutral isn't needed.

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