How To: Wire Solenoid Valves


The best illustration for wiring your solenoid valves is in your Controller instruction booklet. If you don’t have this booklet available, find the model number of your controller and tap Mr Google on the shoulder. There will be plenty of useless pages in the instruction booklet but amongst the last pages there will be a wiring diagram which shows how simple it is to wire solenoid valves.

Wiring for solenoid valves is commonly available in “multi core”. This means there are several individually insulated wires of different colours, wrapped in an outer insulation. Multi core cables are available in 3 core, 5 core, 7 core, 9 core and 13 core.The standard size of the individual wires in any multi core cable is 0.5mm. The wiring compartment in the bottom of your controller will have many terminals with markings such as

“AC” for power

“C” or “VC” meaning common

“MV” or “P” meaning Master Valve or Pump Start

1,2,3,4,5,6,etc identifying the zones

The size of your multi core cable is determined by the number of solenoid valves. You will need one individual wire for each solenoid valve and one common wire to be shared by all the solenoid valves. For example if you have 4 solenoid valves to wire, a 5 core cable will provide one wire for each solenoid valve and one common to be shared by all solenoid valves.

Note: It is always recommended not to skimp on wiring capacity. We recommend always having at least 2 spare wires when choosing your multi core cable.

To begin wiring at the controller, with the power off, pull back the outer sheathing exposing the individual wires. Strip 10mm off each of the individual wires. We are in the habit of using white for the common wire however the colour you use isn’t important as long as the colour of your common wire is consistent.Place your common wire onto the common terminal.

We are in the habit of using black for the master valve wire however the colour you use isn’t important as long as you use the same colour at the master solenoid valve. If you are using a master solenoid valve, place master valve wire onto the “MV” or “P” terminal.

Now for your zone wiring, place the remaining coloured wires onto the numbered terminals. Don’t connect wires into terminals that will not be used.

At the solenoid valves, pull back the outer sheathing exposing the individual wires. Strip 20mm off each of the individual wires. Take 1 wire only from each of the solenoid valves ( not important which of the 2 wires you take ), take the coloured wire you have chosen as your common wire and twist them all firmly together. If you have 4 solenoid valves, you have now twisted 5 wires together including your common wire.

If you are using a Master solenoid valve, take the remaining wire ( the other wire is joined with the common wires ) and twist it to the end of the wire you have chosen as your master valve at the controller. One by one, take the remaining solenoid valve wire and twist them onto their own coloured wire.

Seal all wire joints with a waterproof joiner. Our preference is for heat shrink caps. Turn on your controller, program, and manually test. If you don’t like the order of the zone layout, simply move the zone wires around to your liking

As a general rule, voltage drop will limit the ability of .5mm cable to be effective in carrying  power beyond 100 metres. If your solenoid valves are further than 100 metres from the controller then it will be necessary to double up your common wire or use a multi core cable containing bigger wires. Multi core cable is also available in 1.00mm, 1.5mm.

Note: While web based technology is commonly available for controllers, there are no domestic systems to our knowledge which operate using wireless technology between the controller and the solenoid valves


A Master solenoid valve is a solenoid valve often installed at the head of your water supply which, when wired to the “MV” or “P” terminal, will open at the same time as any of your zone solenoid valves. The Master solenoid valve operates as an “insurance” valve. In the unlikely event of one of your zone solenoid valves sticking open, it is very unlikely that the Master solenoid valve would stick open as well, therefore water will be prevented from running continuously.

Master solenoid valves are a sensible idea when your system involves the installation of a main pipeline. Should the main pipeline be damaged during gardening, fencing, building etc, the Master solenoid valve will be closed when no watering cycle is in operation, therefore preventing a flood.

Note: A garden tap installed into a main pipeline governed by a Master solenoid valve will only have water available when the master solenoid valve is opened, either electrically or manually.

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