How to Hook Up Irrigation Controllers for Lawn Sprinklers

Connecting sprinkler timers, the brains for irrigation sprinkler systems, is typically the last step before back filling the trenches dug for the system piping. Making the electrical connections is a relatively simple process and an appropriate do it yourself project.

Materials List

Only a few materials and common tools are needed for this project.

Screwdriver
Wire cutter/stripper
Electrical conduit (PVC pipe)
Multi-strand, outdoor rated, electrical wire
Wire nuts (Waterproof or use grease caps)

Installing the Irrigation Sprinkler Timer

Using the hardware supplied by the manufacturer, install the irrigation sprinkler controller at a convenient location. The location chosen may be indoors or outside as long as it is near an electrical outlet. If an outdoor site is selected the timer must be rated for outdoor use.

Running the Wiring

Run a sufficient length of multi-strand outdoor-rated electrical wire from the site of the sprinkler controller to the automatic irrigation valve locations. In most cases the irrigation system piping trenches can be used for running the electrical wiring. Consider running the wiring through conduit to protect the wire. PVC pipe serves well as inexpensive electrical conduit.

The number of strands needed in the multi-strand wire used is determined by the number of automatic irrigation valves used in the system. Allow one individual wire for each valve plus one. (e.g., a system with five automatic valves would require six-strand wire).

Wiring the Irrigation Valves

Multiple valves are typically installed at one location in a manifold configuration to simplify the electrical installation. Notice that each automatic irrigation valve has two wires. Using wire nuts, join one wire from each irrigation valve, it doesn't't matter which wire, to one of the wires from each of the other valves. If for example, there are five valves, one wire from each, a total of five wires will be joined to each other.

Prepare the multi-strand wire running from the timer site by stripping back about an inch of the exterior insulation. Separate the individual wires and prepare those that will be used by stripping about one-half inch of insulation from each individual wire. The wires are color-coded. There will be one white and the remaining wires will all have different colors.

The white wire is used as the common. Join it to the wires from each of the valves that were joined in the previous step and secure the connection with a wire nut. Connect a different colored wire to one of the remaining wires of each valve. Keep track of the color of wire attached to each valve as that information will be needed later when connecting the timer.

Wiring the Sprinkler Controller

Return to the timer installation site. Strip and prepare the multi-strand wire at that end in the same fashion as was done for the irrigation valves. Locate the terminal strip for the controller. Connect the white wire (common) to the common terminal that will also be color coded white. Secure the connection with a screwdriver.

Connect one wire to individual zone terminal points which typically are labeled as numbered zones (or stations) on the terminal strip. The colored wire for the zone 1 valve is connected to the terminal point for zone 1, the wire for the zone 2 valve to the terminal point for zone 2 and so on.

Once all of the terminal connections have been secured, attach the power supply cord to the controller and then plug the other end into the electrical outlet used to supply power to the timer.

Test the Sprinkler System Timer

The final step is testing the sprinkler system timer. Manually run each zone to make certain that the wiring has been connected properly and that there are no short circuits. After the test, the controller can be programmed according to the instructions contained in the manual provided by the manufacturer.

Sources

Residential Sprinkler System Design Handbook. Hunter Industries. Web. 30 June 2010.

Layout Guide. Orbit Irrigation Products, Inc. Web. 30 June 2010.