Understanding 3-way Switches

Understanding 3-way Switches


Definitions

Single pole: Your ‘average’ switch- the light is controlled from one location.

3-way: When the light is controlled from two locations. Also called upstairs/downstairs switches in some regions.

Primary switch: In a 3-way installation, the Primary switch contains the Z-Wave chip. The device used in Single pole applications is the Primary - same device.

Add-on switch: In a 3-way installation, the Add-on switch gives an alternate switch location. An Add-on switch CANNOT be used by itself as a Primary switch and is only used with a Primary.

Load: The light, fixture, or other item you want to turn on/off/dim.

Line: The source of the electricity from the electric box/fuse box.

Neutral: The return route of electricity. When installing a Smart Switch, a neutral is required. See What to Know Before Changing Your Wall Switch for more on Neutrals.

Toggle: Type of switch that sort-of looks like an older ‘standard’ switch, and will fit toggle face plates. NOTE: Smart Toggles do not have an “up” and “down.” The switch itself is pressed up or down, but will return to a neutral position. They don’t match standard switches exactly in either look OR resting position.

Rocker: (also called a paddle switch) Type of switch with a wider surface than the toggle. Most modern homes have rocker switches, and this is among the first upgrades done by DIYer’s.

Understanding 3-way Circuits

A 3-way switch is a setup where a load is controlled from 2 locations. There are also 4-way (3 locations), 5-way (4 locations) and even 6-way (5 locations) or more. For Z-Wave purposes (and this blog entry) we are writing about how to install GE JASCO 3-Way Smart Switches. NOTE: most Z-Wave devices will support up to a 5-way switch.

Why is it called a 3-way? I’ve been told that it’s because there are 3 ways for the electricity to flow, or that originally there were 3 points of contact. Nothing seems to make sense to me, and I will leave the nomenclature for electricians and scholars. The average DIY handyman/woman will need to know a single pole switch and a 3-way.

You’ve got a 3-way that you want to add to your Z-Wave network. Now what? The first step in automating your basic 3-way setup is identifying the wiring. There are at least 5 ways of wiring a 3-way switch, and each of those will require a slightly different setup. As we do not give electrical advice on this blog, we will demo the “standard” way that professionals will wire a 3-way circuit and include the steps (and illustrations) from the GE 12723 Add-on Switch instruction sheet below. Know that there may be other ways before you play “Eeny, meeny, miny, mo” (yes, it happens) with the ‘extra’ wires. When in doubt, call an electrician. Part of identifying wiring is understanding that Smart Switches require a line and a neutral wire.

What is an Add-On Switch?

GE switches can be broken up into 2 main categories: Primary Switches and Add-On Switches. A Primary (also known as a Master) switch contains the Z-Wave chip. It’s the more expensive of the pair. If you are only replacing one switch (non 3-way) then you would choose a Primary switch and be done.

An Add-on (also known as a slave or auxiliary) switch gives an alternate location to control the Primary switch. Despite it’s name, it will not let you “Add-On” another switch to your Z-Wave network since it does not have a Z-Wave chip. An Add-on is required when you want to automate a 3-way circuit. The old, existing dumb switch will NOT serve as an Add-on switch.

What is the difference in Model Numbers?

(Click on the model number to open the product page in a new tab).

The GE Smart Primary Switches

Rocker  On/Off Switch is model 12722 and Dimmer is model 12724

Toggle  On/Off Switch is model 12727 and Dimmer is model 12729

The GE Add-on Switches

Rocker (to match 12722 or 12724) is model 12723

Toggle (to match 12727 or 12729) is model 12728

NOTE: Add-on switches will ‘become’ the type of device it supports; a dimmer becomes a dimmer; a switch becomes a switch.  

Steps for replacing existing 3-way switches

 

The above illustration is courtesy GE/JASCO and is from the 12723 Add-on switch instruction sheet.

These instructions are just to help clarify the information on the installation instructions, and do not replace the complete GE/JASCO instructions found here.

1. Shut off power to the circuit at circuit breaker or fuse box.
IMPORTANT! Verify power is OFF to switch box before continuing.
2. Remove both wall plates.
3. Remove the switch mounting screws.
4. Carefully remove both switches from each switch box location. DO NOT disconnect the wires yet .
5. Identify switch connected to fuse box. This is the “Line Switch”. Label wire connected to Common terminal, ‘LINE’.
6. Identify switch connected to lighting/fixture. This is the “Load Switch”. Label wire connected to Common terminal, ‘LOAD’.

The above illustration is courtesy GE/JASCO and is from the 12723 Add-on switch instruction sheet.

Switch Connected To Fuse Box “Line Switch”
(Replacing standard switch with GE Primary Switch)
1. Disconnect all wires on existing switch.
2. Locate neutral wires found inside switch box. Remove wire nut securing them. (A). (These are typically a bundle of white wires in the back of the box)
3. Locate jumper wire (included in packaging of primary switch). Connect with neutral wires and secure again with wire nut previously removed. (A).
4. Connect opposite end of jumper wire to NEUTRAL terminal on Primary Switch (B).
5. Connect wire you previously labeled, ‘LINE’ to LINE terminal on Primary Switch (C).
6. Connect ground wire (bare/copper/green) to GROUND terminal on Primary Switch (D).
7. Connect one of the two remaining wires (T1) to LOAD terminal on Primary Switch (E). Write down the color of the wire. You will need this when installing the add-on switch.
8. Connect the remaining wire (T2) to TRAVELER terminal on the Primary Switch (F)

Switch connected to lighting “Load switch”
(Replacing standard switch with GE Add-on Switch)
1. Disconnect all wires on existing switch.
2. Locate neutral wires found inside switch box. Remove wire nut securing them. (AA). (These are typically a bundle of white wires in the back of the box)
3. Locate jumper wire (included in packaging of primary switch). Connect with neutral wires and secure again with wire nut previously removed. (AA).
4. Connect opposite end of jumper wire to NEUTRAL terminal on Add-on Switch (BB).
5. Connect ground wire (bare/copper/green) to GROUND terminal on Add-on Switch (CC).
6. Locate the same colored wire you wrote down previously in the switch box (T1). Using a wire nut , secure it only to the wire you previously labeled, ‘LOAD’ .
7. Connect the remaining wire to TRAVELER terminal on the Add-on Switch (DD). This will be the same color as the wire connected to TRAVELER terminal on the Primary Switch.

Attach switch to Box

1. Carefully place both switches into their respective switch box, being careful not to pinch or crush wires.
2. Secure each switch to the box using the supplied screws.
3. Mount each switch wall plate.
4. Reapply power to the circuit at fuse box or circuit breaker and test the system.

The above text is courtesy GE/JASCO and is from the 12723 Add-on switch instruction sheet. 

are Two or more switches in the same box considered a 3-way?

When you have multiple switches in the same box, this is called a multi-gang switch installation. Although you MAY have one or more 3-way circuits in a multi-gang box, each of the switches in that box will be it's own circuit. Handle these like any other single gang installation with one caveat: You may not be able to fit multiple Smart Switches next to one another. In this case follow the manufacturer's instructions on how to clip/break off the heat sink tabs on the sides of the switch.

This will allow you to fit more switches side-by-side, but removing tabs will decrease the load rating of the switch. Read the instructions that come with the switch for more information.

 

Have questions? See any errors/omissions/confusion? Please fill out our Ask An Expert form for more help with your Z-Wave installation projects. 

 

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