Standard Socket Wiring

Figure 1: Socket connected to the Ring Circuit (Ring Main).

A typical mains socket will be part of a 'Ring Circuit' (often called a Ring Main). The ring main forms a circular circuit allowing current to be supplied to the socket from two directions. For this reason, each socket on the ring main will have two live cables, two neutral cables and two earth cables (not shown in figure 1.)

Relay Connections

Figure 2: Controlling the socket with a Fibaro Relay wired via a Fused Spur.

A Fibaro 1x3Kw Relay (FGS-211) can be used to control the socket as shown in Figure 2.

You will see that the circuit uses a Fused Spur between the Fibaro Relay and the ring main. This is because building regulations state that no appliance (including a relay) can be connected directly to the ring main without being protected by a fuse. This provides protection to the house's wiring should the relay develop a fault - not including a fused spur could create a hazard and may invalidate your home insurance.

This will enable the socket to be controlled wirelessly via the Z-Wave Controller. You can also install a switch so that you can control the relay manually.

Earthing

All electrical circuits MUST be correctly Earthed.

All cables used in ring main circuits contain a bare Earth wire - this typically has a green/yellow sleeve when it is wired to the socket or backbox. The Earth is a very important part of the electrical system and all switches, appliances and sockets must be correctly earthed.

For simplicity we do not show the earth wire in these drawings or explanations as it plays no active role in the day-to-day workings of your power circuits, it is there for your protection in case of emergency.