Smart Home Singapore - Electrical Wiring Guide for Z-Wave Switches

[AutomateAsia 2]

Electrical Wiring Guide for Z-Wave Switches

I’ve recently guided an electrician on the wiring required for Z-Wave wall switch. Before successfully installing the Z-Wave switch, he actually used a neutral wire from some other part of the house and it caused a power trip. So, I invited him to my place to look at the wiring as a reference and he eventually managed to install the switches successfully.

In this short article, I’d like to take this opportunity to show you how a normal light switch is being wired and how you should ask your electrician to lay neutral wire to the light switch.  I’d also take the chance to explain why Z-Wave light switches require a neutral wire. (Disclaimer: I am not an electrician nor have a degree in electrical engineering but my explanation is based on logic, research and some basic electrical knowledge from secondary school.)

Wiring for Conventional Light Switch

Wiring for Z-Wave Switches

Closed circuit in off state

Closed circuit in on state

For Z-Wave switch, in off state, the neutral wire keeps the circuit closed to power the switch module. This is the reason a neutral is required for Z-Wave switches.

Wiring for Conventional Dimmer

Wiring for Z-Wave Dimmer (on or off state)

For Z-Wave dimmers, in the off state, the circuit is always closed and a small current is always running through the lights to power the dimmer module, except that the current is not sufficient to light up the bulb. This is the reason a neutral wire is not required for Z-Wave dimmers.

I hope you will be able to use the above information to guide your electrician who is not versed in installing Z-Wave switches.

AA - Domotics