Rain Sensor Installation (Gen 2)


Rain sensor installation

Spruce accepts many standard “normally closed” rain sensors from a variety of manufacturers.  Passive rain sensors can be installed using the “S1 or S2” input terminals and the “C” terminal located below the S2 terminal.  Powered rain sensors can have power supplied by the 24 VAC and common terminal below the S2 terminal on the Spruce controller.  The diagrams below show a installation schematics using 4 different rain sensors: Rainbird, Hunter, Irritrol and Orbit.

“Normally closed” refers to the operation condition of the rain sensor.  A rain sensor is “normally closed” when the 2 wires conduct if the sensor is dry.  The connection is “opened” when the sensor is wet.  This is the most common type because this allows the sensor to “break” the power connection going to the irrigation valves if rain is detected.

The Spruce controller must be configured to use a rain sensor in the app.  If the rain sensor is not enabled in the app, the system will not delay watering even if a sensor is attached.

The terminals S1,S2,C, and 24V grouped together on the right hand side are for sensor input and power only.  These terminals may not be used for valve common or power and can not be used for powering the unit.

Rain sensor enable

If a rain sensor has been installed, the operation will then need to be enabled in the Spruce app.

The Rain sensor terminal are setup for Normally Closed rain sensors, this means if the terminal is enabled and a sensor is not attached it will think there is Rain, ONLY enable sensors after confirming they are wired correctly.

  1. Navigate to the “Device Settings” page
  2. In the devices tree, click or touch the name of the controller you wish to edit (generally, this will be the first item in the tree)
  3. In the Controller Settings screen that appears, scroll down to the External Inputs section.
  4. Select “Rain Sensor” on the 1st or 2nd input which matches the rain sensor terminal you have attached on the physical controller
  5. Save

After a rain sensor has been enabled, each schedule and zone has the option to use the rain sensor as means to skip watering.  See scheduling setup and options on enabling rain delay specifically for each schedule or zone.

Wireless Rain Sensors

Four common wireless rain sensor wiring instructions are referenced below.  Wire colors may have changed, and the instructions provided by the manufacturer should be followed when attaching the sensor.

Rainbird WR2

Irritrol RS1000


Hunter CLIK


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