IMPORTANT - Read this first!
Note: To simplify these diagrams, we have not shown the earth cables - but all circuits MUST have the earth cable correctly installed.
We've shown wires in red to indicate that they are new wires, but it doesn't really matter what colour you use.
To protect the module a suitable rated overcurrent protection fuse must be installed on the Live input.
We work hard to keep these wiring guides accurate and up to date and would appreciate any feedback, corrections or suggestions that you may have. Please contact us using our help page or by simply emailing feedback@vesternet.com
One of the things that confuses people the most is installing home automation into an existing 2-Way lighting system. This application note looks at how a Fibaro Dimmer 2 module can be installed to control a Standard 2-Way Lighting Circuit with Neutral available.
Firstly, what do we mean by 2-Way lighting?
This simply refers to a lighting system where one light is controlled by two light switches. Examples of this are where a room has two entrances (each needs a light switch) or for a hall light that can be controlled from the hall and the upstairs landing.
More information about 3-Wire lighting systems is available in APNT-23: Understanding 2-wire and 3-wire Lighting Systems.
For information on how to physically install a Z-Wave module take a look at our guide here.
To know more about how Z-Wave modules work with different switch types make sure to read our guide here.
Standard 2-Way Lighting Circuit (with Neutral)
Figure 1: Standard 2-Way Lighting Circuit (with Neutral).
2-Core cables (brown and blue) carries Live and Neutral to the wall switch and Switched Live and Neutral up to the light fitting. An extra 3-Core cable (brown, black and grey) connects the two wall switches together, enabling each of them to independently turn the light On or Off.
This type of lighting system uses "Toggle" (latching) switches. These latch in position - for instance when you press the switch to On, the switch physically stays in the On position. These are the standard light switches you'll find already fitted in your home.
The module can also be used with a variety of "Momentary" switch types and configurations. Momentary switches, also known as Retractive or Bell-Push, only remain in the On state while you press them, they return to the Off state when the button is released.
This doesn't mean that you have to keep holding the button to keep the light on. The module's internal controls automatically keep the light on when the button is released.
More information about how the Fibaro Dimmer 2 works with different switch types is available here.
We can install the module into this 2-Way circuit in various different ways shown below. We've separated out the diagrams based on whether you need to install the module at Switch A or Switch B position.
Installation at Switch A position
This is probably the most common of requirements, you will install the module at the Switch A position where it has access to both the 2-Core wires and the 3-Core wire.
Toggle Switches
To retain your existing standard Toggle switches, we can simple install the module as shown in Figure 2.
Figure 2: Standard 2-Way Lighting Circuit (with Neutral) using the Fibaro Dimmer 2 with Toggle switches.
In this case we keep the standard Toggle switches connecting "L1" to the module's S1 input with the "L2" wire connected to the module's Sx output. Live and Neutral are wired to L and N terminals respectively.
This gives simple On / Off control of the light from the switches but you will still be able to control the dimming level over Z-Wave if required.
Fibaro Dimmer 2 Parameter Setting:
The following parameters need to be set:
- 20 - 1 - enables the module to work with a toggle switch (default is 0 for a momentary switch)
Toggle Switches - Alternate
Another option to use standard Toggle switches is to install the module as shown in Figure 3.
Figure 3: Standard 2-Way Lighting Circuit (with Neutral) using the Fibaro Dimmer 2 with Toggle switches.
In this case we keep the standard Toggle switches connecting Switch A "L1" to the module's S1 input and Switch B "L1" to the module's S2 input with the "COM" wire connected to the module's Sx output. Live and Neutral are wired to L and N terminals respectively.
Any unused wires from the original 3-core between the two switches should be safely terminated.
The module is then configured to accept S2 as the second switch control of the module.
This gives simple On / Off control of the light from the switches but you will still be able to control the dimming level over Z-Wave if required.
Fibaro Dimmer 2 Parameter Setting:
The following parameters need to be set:
- 20 - 1 - enables the module to work with a toggle switch (default is 0 for a momentary switch)
- 26 - 1 - enables the modules' S2 switch to also control the dimmer (default 0)
Momentary Switches
For full On / Off and dimming control we can replace the Toggle wall switches with similar styled Momentary switches.
Figure 4: Standard 2-Way Lighting Circuit (with Neutral) using the Fibaro Dimmer 2 with Momentary switches.
By using Momentary switches, the 2-Way wiring can be simplified - simply connect both Switch A and Switch B "L1" to the module's S1 input and the "COM" wire to the module's Sx output. Live and Neutral are wired to L and N terminals respectively.
Any unused wires from the original 3-Core between the two switches should be safely terminated.
Fibaro Dimmer 2 Parameter Setting:
The following parameters need to be set:
- 20 - 0 - keep as default to work with a momentary switch
Multi-Way install with Momentary Switches
Using the module with Momentary switches enables the easy creation of 3-Way lighting circuits, in fact an infinite number of Momentary switches can be wired in parallel to create 3-, 4-, 5-, 6-way... lighting systems.
Figure 5: Multi-Way Lighting Circuit (with Neutral) using the Fibaro Dimmer 2 with Momentary Switches.
Simply add on as many Momentary switches as you require by extending the "L1" and "COM" wires. Any unused wires from the original 3-Core between the switches should be safely terminated.
Fibaro Dimmer 2 Parameter Setting:
The following parameters need to be set:
- 20 - 0 - keep as default to work with momentary switch
3-Position Momentary Switch
You can also use "3-position" Momentary switches in the same way with the module. These switches can give a more intuitive control for the user because it operates like a traditional rocker switch with up and down push positions which work well for dimming up, dimming down and on / off commands.
Figure 6: Using 3-Position Momentary switches (with Neutral) using Fibaro Dimmer 2.
To install this type of switch you simply leave the 3-Core wired between the switches intact and connect the "L1" wire to the module's S1 input, the "L2" wire to the module's S2 input and the "COM" wire to the module's Sx output. Live and Neutral are wired to L and N terminals respectively.
Fibaro Dimmer 2 Parameter Setting:
The following parameters need to be set:
- 20 - 2 - enables the module to work with a 3-position switch (default is 0 for a momentary switch)
Multi-Way 3-Position Momentary Switch
It's easy to extend the 3-Position Momentary switch installation into a multi-way lighting system by extending the 3-Core wire to other switch positions and wiring in parallel.
Figure 7: Multi-way Lighting Circuit (with Neutral) using 3-Position Momentary switches with Fibaro Dimmer 2.
Simply add on as many 3-Position Momentary switches as you require by extending the "L1", "L2" and "COM" wires.
Fibaro Dimmer 2 Parameter Setting:
The following parameters need to be set:
- 20 - 2 - enables the module to work with a 3-position switch (default is 0 for a momentary switch)
Multi-Way with Z-Wave Wall Switch
Sometimes you may require a 2-Way or multi-way lighting circuit where physical wiring doesn't already exist, or perhaps you need to re-purpose the existing wiring for something else.
Z-Wave makes this possible using something known as "Associations" - where one Z-Wave device can control another Z-Wave device directly without inter-connecting wiring. More information on Associations can be seen in our guides here and here.
Figure 8: Using Z-Wave Switches in a Standard 2-Way Lighting Circuit (with Neutral) with Fibaro Dimmer 2.
To create this circuit you simply install the module to suit either Toggle or Momentary switches and safely terminate the 3-Core cable as required. A battery powered Z-Wave Wall Controller can then be Associated to the module.
Don't forget to configure the module for Toggle or Momentary switches!
Installation at Switch B position
In some circumstances it may not be possible to install the Fibaro Dimmer 2 module at the Switch A position - perhaps there's not enough room physically to install it there, or perhaps that position is out of range of the Z-Wave netwok. In this case sometimes it's possible to install at the Switch B position but there are a number of caveats because in this position it won't have access to both the 2-Core and 3-Core wires.
Toggle Switches - add additional 2-core cable between switches
To retain your existing standard Toggle switches, we can install the module as shown in Figure 9.
Note: An additional 2-core wire is required to be run between the switch positions to be used as Neutral and Switched Live!
Figure 9: Standard 2-Way Lighting Circuit (with Neutral) using the Fibaro Dimmer 2 with Toggle switches at Switch B location.
In this case we keep the standard Toggle switches, connecting Switch A "L1" to the module's S1 input and Switch B "L1" to the module's S2 input with the "COM" wire connected to the module's Sx output. We use the original "L2" wire to bring over Live from the first switch position and an additional 2-core wire is added to take Neutral and Switched Live back to Switch A position.
The module is then configured to accept S2 as the second switch control of the module.
This gives simple On / Off control of the light from the switches but you will still be able to control the dimming level over Z-Wave if required.
Fibaro Dimmer 2 Parameter Setting:
The following parameters need to be set:
- 20 - 1 - enables the module to work with a toggle switch (default is 0 for a momentary switch)
- 26 - 1 - enables the modules' S2 switch to also control the dimmer (default 0)
Momentary Switches - add additional 2-core cable between switches
For full On / Off and dimming control we can replace the Toggle wall switches with similar styled Momentary switches.
Note: An additional 2-core wire is required to be run between the switch positions to be used as Neutral and Switched Live!
Figure 10: Standard 2-Way Lighting Circuit (with Neutral) using the Fibaro Dimmer 2 with Momentary switches at Switch B location.
Here we replace the standard Toggle switches with Momentary switches and connect both Switch A and Switch B "L1" to the module's S1 input and the "COM" wire to the module's Sx output. We use the original "L2" wire to bring over Live from the first switch position and an additional 2-core wire is added to take Neutral and Switched Live back to Switch A position.
Fibaro Dimmer 2 Parameter Setting:
The following parameters need to be set:
- 20 - 0 - keep as default to work with momentary switch
Toggle Switches - re-wire Neutral and Switched Live to Switch B
Figure 11: Standard 2-Way Lighting Circuit (with Neutral) using the Fibaro Dimmer 2 with Toggle switches at Switch B location.
Connect Switch A “L1” to the module's S1 and Switch B "L1" to the module's S2 input with the "COM" wire to the module's Sx output. We use the original "L2" wire to bring over Live from the first switch position and re-wire Neutral and Switched Live to the Switch B position.
The module is then configured to accept S2 as the second switch control of the module.
This gives simple On / Off control of the light from the switches but you will still be able to control the dimming level over Z-Wave if required.
Fibaro Dimmer 2 Parameter Setting:
The following parameters need to be set:
- 20 - 1 - enables the module to work with a toggle switch (default is 0 for a momentary switch)
- 26 - 1 - enables the modules' S2 switch to also control the dimmer (default 0)
Momentary Switches - re-wire Neutral and Switched Live to Switch B
Figure 12: Standard 2-Way Lighting Circuit (with Neutral) using the Fibaro Dimmer 2 with Momentary switches at Switch B location.
Here we replace the standard Toggle switches with Momentary switches and connect both Switch A and Switch B "L1" to the module's S1 input and the "COM" wire to the module's Sx output. We use the original "L2" wire to bring over Live from the first switch position and re-wire Neutral and Switched Live to the Switch B position.
Fibaro Dimmer 2 Parameter Setting:
The following parameters need to be set:
- 20 - 0 - keep as default to work with momentary switch
2-Way with Z-Wave Wall Switch
Figure 13: Using a second Dimmer 2 S2 input in a Standard 2-Way Lighting Circuit (with Neutral) with Fibaro Dimmer 2.
Here we replace Switch A with a Z-Wave Wall Switch. Connect Switch B “L1” to the module's S1 input with the "COM" wire connected to the module's Sx output. We use the original "L1" wire to bring over Live from the first switch position, re-wire “L2” to take Switched Live and "COM" to take Neutral back to Switch A position. Any unused wires from the original 3-core between the two switches should be safely terminated.
A battery powered Z-Wave Wall Controller can then be Associated to the module. More information on Associations can be seen in our guides here and here.
Install at Switch B and use S2 from Dimmer 2 at Switch A
Figure 14: Using Z-Wave Switches in a Standard 2-Way Lighting Circuit (with Neutral) with Fibaro Dimmer 2.
Here we connect Switch A “L1” to Module A S2 input. Connect Switch B “L1” to the Module B S1 input with the "COM" wire connected to the Module B Sx output. We use the original "L1" wire to bring over Live from the first switch position, re-wire “L2” to take Switched Live and "COM" to take Neutral back to Switch A position. Any unused wires from the original 3-core between the two switches should be safely terminated.
More information on how to use a Secondary Switch with a Fibaro Dimmer 2 module can be found here.
Note: power to module at Switch A not shown as this would typically be taken care of for switching the other gang in a 2-gang switch.
