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What are the color conventions for wiring 4-way switching?

What are the color conventions for wiring 4-way switching?

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  #1  
Old 02-08-06, 10:49 AM
wgc
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What are the color conventions for wiring 4-way switching?

I'm thinking of installing a four way switch (light to be switcheable at each of the three entrances to a room) and can figure out how to connect the wires but have no idea of the color/labelling conventions or requirements.

Trying to generalize from the simpler cases, I'm going by:
- black and red may be hot regardless of the switch position
- white should not be hot if switch is off
Does this sound good? I vaguely remember something about color labelling with electrical tape in non-standard situations, but don't remember any details.

Hopefully I can describe this adequately without a picture:
- 14-2 from power to light. White connects to white on light. Black connects to next black. Black on light connects to next white.
- 14-2 from light to 3-way switch. White connects to next white. Black connects to center terminal. Other terminals connect to black and red of next cable.
- 14-3 from 3-way to 4-way. White connects to next white. Black and read connect to one side. Next black and red connect to other side
- 14-3 from 4-way to final 3-way. White connects to center terminal. Black and red connect to other terminals
- grounds connected all the way through
 
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  #2  
Old 02-08-06, 11:11 AM
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You have made a mistake. It's not a significant one, but one nevertheless.

First, regarding marking. Code requires that when you use the white wire of a multi wire cable as a hot conductor that you re-identify it. You do this at each end, by using a small piece of electrical tape around the wire, or by coloring it with a permanent marker. You can use just about any color, except white or green.

Now your mistake. You have wired a switch loop. Code requires that for a switch loop the switched hot wire may not be the white wire, even when you have re-identified it as hot. You need to remake your connections.
 
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Old 02-08-06, 03:14 PM
wgc
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which can't be white

Well, I haven't made the mistake yet, but intend to this weekend ;-) I'll use whatever color for whatever purpose the code asks but don't fully understand your advice. What do you mean by a "switched hot"? It seems like any of the conductors in the set of switches could fall into that definition.
 
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Old 02-08-06, 04:32 PM
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The light fixture must have a white neutral wire connected to it and a switched hot wire. The switched hot wire can not be a remarked white.
 
  #5  
Old 02-08-06, 04:34 PM
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Let's use a simple example, a switch loop for a two way switch. In this switch loop you have a black and a white wire. In this case, one of the wires will always be hot (the wire that takes power to the switch), and the other wire will be a switched hot (the one that brings power from the switch, when the switch is on). In this case, code requires that the wire that brings power back from the switch be black.

If you follow this same algorithm in the case of multiple switches, the wires (and there are more than one) that bring switched power to the light need to be black.
 
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Old 02-08-06, 07:28 PM
wgc
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any idea why?

Ok, will do.

But I like to understand things: do you have any idea why? I thought my reasoning sounded more 'natural' or more in the spirit of the simpler cases. You're saying the code essentially requires a hot to be a marked white. Why would that be any safer or more predictable (aside from the fact that it's in the code)?
 
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Old 02-08-06, 08:14 PM
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The switched wires don't actually need to be black. They just can't be white or grey or green. They are very often red and if conduit is used could be blue or yellow or other colors.
 
  #8  
Old 02-08-06, 08:33 PM
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Re-identification methods degrade over time and can confuse the next homeowner. You want a black (or any color other than green or white) wire and a white wire to attach the light to. That way - it's very clear to everyone installing a new fixture in that box which wire is hot and which is neutral.
 
  #9  
Old 02-08-06, 08:47 PM
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Originally Posted by wgc
do you have any idea why?
Yes. A white attached to a switch is always hot (an UC).
A white attached to a colored (e.g., black) is always hot.
A white attached to a fixture is always a GC (neutral).

Any other system is ambiguous and therefore hazardous.



You're saying the code essentially requires a hot to be a marked white.
No, never.

A white is always neutral except that in a switch leg or as traveler, it can be hot and must be re-marked with a permitted color (not white, grey, or green).
It must terminate at a colored wire or on a switch - never on a fixture.

A fixture always has exactly one white wire attached to it.
No confusion there.
 
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