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The following wiring diagrams and schematics are for reference only. There may be situations that require custom wiring options. Contact W.P. Law, Inc. for custom applications and if you are unsure of the application's wiring requirements. Note that on the downloads, if the picture comes up rotated in Adobe Reader, simply press (Ctrl, Shift, +) or right-click on the image and then click "Rotate Clockwise" to view the image upright.
This diagram shows how to wire a pump using a simple pump start relay controlled by an irrigation controller.
PSR Diagram Dual Irrigation Controllers with a Single Pump
This diagram shows how to wire a single pump to a pump start relay that is being controlled by two separate irrigation controllers. This diagram utilizes two relay switches to prevent voltage from back feeding from one irrigation controller to the other.
DICSP DiagramIsolator Wiring Diagram
This diagram shows how to wire a single pump to a pump start relay that is being controlled by two separate irrigation controllers. This diagram utilizes a product called an Isolator. The Isolator acts as a relay, as well as having some other electrical protection built in, and is an alternative to the option above.
IWD Diagram Pump Start Relay with Manual On/Off Switch
This diagram shows how to wire a pump using a simple pump start relay controlled by an irrigation controller, but also with the option to turn the pump on manually via a switch.
TPP-2 Diagram Pump Start Relay/Pressure Tank Combo (High Head Centrifugal)
This diagram shows how to wire a pump using both a pump start relay and a pressure tank with pressure switch. This is useful to prevent excessive cycling when using a high head centrifugal pump for irrigation purposes. This wiring schematic also allows the system to remain pressurized for water on demand applications.
PSRPT Diagram Pump Start Relay/Pressure Tank Combo (Submersible Well Pump)
This diagram shows how to wire a pump using both a pump start relay and a pressure tank with pressure switch. This is useful to prevent excessive cycling when using a submersible well pump for irrigation purposes. This wiring schematic also allows the system to remain pressurized for water on demand applications.
PSRPTS Diagram Single Float Cistern
This diagram shows how to wire a pump in conjunction with a cistern tank using a single float switch and simplex controller. This setup allows for drainage water to be pumped out of the cistern for the irrigation. If the cistern is full, the pump will utilize that water first. Once the tank is emptied, a backup water source (either city water or well water) will then be used by activating a master valve. This setup ensures the drainage water is utilized first and the cistern is left emptied, able to collect drainage water from future rainfall events.
TPP-1 Diagram Dual Float Cistern With Autofill
This setup is typically used when the flow rate of the irrigation system exceeds the flow rate of the water source. In this situation, a cistern or tank is used as a reservoir to supply additional water for the irrigation. There are two float switches: one is to prevent the irrigation pump from running when the tank is empty, and the other is to turn the fill valve on and off.
TPP Diagram 
Irrigation Valve Wiring Diagram
This diagram shows the basic way to wire irrigation valves to the controller.
IVW Diagram Doubler Wiring Diagram
This diagram shows how to wire a product called a Doubler. This product allows for an extra zone to be added without having to run wire all the way back to the clock. There are several scenarios where the Doubler is useful and they are explained in the diagram.
DID Diagram Click-It Wiring Diagram
This diagram shows how to wire a Click-It. This product is useful for locating irrigation valves in the field. By wiring a Click-It in line with the common on the clock, the valve you are trying to locate will produce an audible "clicking" or "pinging" so that you can locate it.
CIWD Diagram