One of the frequent pieces of advice I’ve gotten has been to make sure that I use 3-wire cabling in my new construction to allow for easy swap out to z-wave switches/dimmers. I want to confirm a few things.
3-wire cabling is actually four wires correct? 3 wires + a ground?
Can 3 wire cabling be done just in areas that I may want z-wave?
For a “common” 3000 sq foot home how much more does 3 wire cabling cost than 2 wire?
Does the 3 wire cabling need to be at outlet locations or just switches?
You only need proper 3-way (or 4-way) wiring in places where you might want 3-way switches:
each end of a hallway
top and bottom of stairs
multiple entrances to a room
3-way wiring is usually
black
white
red (traveler)
ground
You only need the “traveler” wire (red, usually) between the 2 (or more) switches. It isn’t needed going from the panel to SwitchA, nor from SwitchB (or the last switch) to the light/load.
You do not want 3wire every where … if you have multi-gang boxes you may run out of room for switches with all the wires in there.
Have them install the deepest boxes!
3Way (3Wire) is also useful for Exterior lights (turn them on all from anywhere)
You just need to decide all of the places where you need multiple points of control.
3 Wire is also used to tie all of your smoke detectors together.
So if I understand - the standard wiring for a standard 3-way switch setup would put allow me to switch to a z-wave 3-way setup (master/controller - e.g. Leviton VRI06-1LZ & VP00R-10Z)?
So where is it that the standard wiring won’t work for z-wave? A standard single pole wiring?
3-Way cabling is to allow multiple switches to control the same circuit.
You want 3-wire cabling so that you have a neutral and ground available in every box. Good zwave switches need a neutral so the switch can be powered without drawing power through the lights on the circuit. If you are drawing even a small amount of power through a cfl or LED fixture it may be enough to light it up slightly even when its turned ‘off’.
[quote=“Freakin, post:5, topic:175821”]I think there is some confusion here.
3-wire cabling is
Hot
Neutral
Ground
3-Way cabling is to allow multiple switches to control the same circuit.
You want 3-wire cabling so that you have a neutral and ground available in every box. Good zwave switches need a neutral so the switch can be powered without drawing power through the lights on the circuit. If you are drawing even a small amount of power through a cfl or LED fixture it may be enough to light it up slightly even when its turned ‘off’.[/quote]
Actually, I don’t think that is the case (ground isn’t counted in the number):
2-wire is usually: black, white, ground
3-wire is usually: black, white, red* + ground
But that makes the blanket advice of “use 3-wire to work with zwave” pretty pointless, since the traveler wouldn’t have anywhere to go in the majority of applications.
Use 3-wire where you want multiway switches, otherwise use 2-wire.
[quote=“PurdueGuy, post:6, topic:175821”][quote=“Freakin, post:5, topic:175821”]I think there is some confusion here.
3-wire cabling is
Hot
Neutral
Ground
3-Way cabling is to allow multiple switches to control the same circuit.
You want 3-wire cabling so that you have a neutral and ground available in every box. Good zwave switches need a neutral so the switch can be powered without drawing power through the lights on the circuit. If you are drawing even a small amount of power through a cfl or LED fixture it may be enough to light it up slightly even when its turned ‘off’.[/quote]
Actually, I don’t think that is the case (ground isn’t counted in the number):
2-wire is usually: black, white, ground
3-wire is usually: black, white, red* + ground
*red is common for traveler, but others exist.[/quote]
Correct. Ground is not considered a “wire” since in theory it should never conduct anything. It is a safety shield in case a hot wire comes loose and contacts anything that you could then touch and get a shock. In theory it would short to the ground and blow the circuit breaker. That’s why it’s usually referred to as “2 wire plus ground” or “3 wire plus ground”, or more correctly “2 conductors plus ground” or “3 conductors plus ground”.
It’s 3 wire (+ ground) between multi-way switchs and smoke detectors.
It’s 2 wire (+ ground) from Fuse box to first switch and from switch to lights
unless there is a fan/light combo … than it’s 3 wire from switch to fan/light.
So can anyone clarify this for the rest of us that are…electrically challenged? Installation of a Z-wave switch, how many wires do we need? 3+ground? What are the 3? 2 phases and one neutral? 1 phase and 2 neutrals? Thank you.
What Richard said, Its pretty standard to have a neutral in all switch boxes in newer homes, and i believe its part of the NEC code now anyway. to answer your question about how many wires you need, for a single pole zwave switch you will need one hot and one neutral depending on brand and type, some switches do not need a neutral.
As far as 3 and 4 way switches go you will have enough wires, they are wired different with zwave but the amount of wires you need is the same. see Richards post. you will only use one zwave switch then the rest will be aux or matching remote switches.
if you are still confused i suggest downloading the installation guide for the switches you are considering.
If you are considering using Intermatic switches, you will need an extra wire from the Z-wave switch to the light when 3 or more switches are used in a circuit.
dogman, it’s not that simple. The following refers to 120V, single phase, U.S. style electrical wiring.
First question is what type of switch? Z-wave switches fall into 2 general categories; dimmers and on/off switches. Dimmers are typically used with standard incandescent lights; they can be used with “dimmable” CFLs and LEDs with varying results. On/off switches use relays and are typically used with fluorescent lamps, CFLs and LEDs if dimming is not desired; they will not lead to flickering of the lights. They can also be used to control loads other than lights (think fans and the like).
For a single switch (not 3-way or 4-way) you only need 2 conductors for a dimmer (line and load; line is the feed from the service panel and load is the feed from the switch to the light fixture, sometimes called the switched hot). For an on/off switch you need 3 conductors (line, load, and neutral).
For a 3-way dimmer switch you need 3 conductors (line, load, and traveler) or 4 conductors for an on/off switch (line, load, neutral, and traveler). Note that normal 3-way (non z-wave) require 2 travelers so you may have extra wires left over when you change to z-wave.
If this is too confusing to you I highly suggest you hire an electrician.
It's 3 wire (+ ground) between multi-way switchs and smoke detectors.
It's 2 wire (+ ground) from Fuse box to first switch and from switch to lights
unless there is a fan/light combo ... than it's 3 wire from switch to fan/light.
This is standard stuff in todays construction!
90% of your wiring in a house is 2 Wire + ground. It’s single phase. Black is from the breaker,
white is from the neutral, and all of the ground wires are tied together to form an “earth” ground. The latter is a safety feature, and should not carry any current in normal use. In fact the GFCI will detect if the current is not the same in the Black and White wire and will trip … it means the current is going to ground some how … like thru you and is designed to keep you from being electrocuted
The use of the 3 Wire + ground is used for a FEW special purposes.
As I indicated they are used for:
Fan Light configurations, with dual wall switches. They travel from the wall switch to the fan/light combo … Bathrooms, Living Areas, Bedrooms, Kitchens, …
They Red wire is used as the Black wire for the second switch. They share the white wire and ground.
Between Multiple 3 Way switches.
Red was traditionally called the traveler. With today’s technology things are wired different than in the past. The extra wire is needed for one switch to talk to another switch. Different Z-Wave vendors, wire this differently, you or the electrician will need to review the particular needs based on the actual Z-Wave switches you purchase.
Tie all of the Smoke detectors together.
The Black and White provide the standard power. The red wire is used to communicate between the smoke sensors. If one triggers, they will all sound the alarm.
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