R-200 Gutter & Surface Mount Rain Sensor
INSTALLATION INSTRUCTIONS
MOUNTING
The R-200 sensor includes 2 mounting options:
1. Rain Gutter
2. Flat Surface
Mount the rain sensor where it will be exposed to direct, unobstructed rainfall (but away from sprinkler spray).
The Switch-housing portion must be upright (See Figure 1).
Hints for mounting:
A. Mount as close as possible to the timer. This will cause the wire run to be shorter, which minimizes the
possibility of wire breaks.
B. Mount in the highest possible position where rain can fall directly upon the rain sensor.
C. As described in the “Adjustments and Operation” section of the manual, “reset rate” refers to the amount of
time it takes the rain sensor to dry out sufficiently for the sprinkler system to be allowed to come back on.
The mounting location will affect this rate and should be taken into consideration should extreme conditions
exist. For example, mounting the rain sensor on a very sunny, southeastern end of a building may cause
the rain sensor to dry out sooner than desired. Similarly, mounting on the northern end of a building with
constant shade may keep the rain sensor from drying soon enough. Some experimentation and use of the
“vent ring” (as described later) will usually yield satisfactory results.
Once the rain sensor is mounted, run the wire to the controller, using wire clips every few feet to fasten it. If an
extension to the wire provided is needed, use the following table to determine the minimum wire gauge needed:
WIRING
IMPORTANT: The rain sensor is sold and designed for 24-VAC irrigation controllers only. All wiring must
conform to applicable local codes. The two most common wiring situations are detailed below for controllers
that do not have direct rain sensor & pump start relay wiring capabilities. For non-standard wiring situations,
please consult your distributor.
A. 24-VAC Solenoid Valves Only (No Pump Start Relay See Figure 2) With the two wires from the rain sensor
at the controller, locate the “common ground” wire of the solenoid valves. If it is connected to the common
terminal on the controller disconnect it. Attach one wire of the rain sensor to the “common” terminal
(usually marked “COM”) on the controller. Attach the other wire of the rain sensor to the common wire
leading to the valves. Note: The common wire to the valves does not have to be interrupted at the
controller.The rain sensor may be wired anywhere along the common wire line.
B. 24-VAC Solenoid Valves with Pump Start Relay (See Figure 3). Locate the common wire to the solenoid
valves and the common wire lead to the coil of the relay that starts the pump. If these two wires are
connected to the “common” terminal on the controller, disconnect both of them. Twist these two wires
together along with one wire from the rain sensor and secure with a wire nut. Attach the other wire of the
rain sensor to the “common” terminal on the controller.
CHECK TO VERIFY CORRECT WIRING
Turn on one zone of the sprinkler system that is visible while you are in reach of the rain sensor. Manually
depress the spindle at the top of the rain sensor until you hear the switch “click” off. The sprinkler zone should
stop instantly. If it does not, check wiring for correct installation.
ADJUSTMENTS AND OPERATION
The rain sensor can keep the irrigation system from
starting or continuing after rainfall quantities of 1/8”,
¼”, ½”, ¾”, or 1”. To adjust it to the desired quantity of
rainfall, rotate the cap on the switch housing so that
the pins are located in the proper slots (See Figure 4).
Do not forcibly twist the cap as this might break the pins.
The time that it takes the rain sensor to reset for normal
sprinkler operation after the rain has stopped is determined
by weather conditions (wind, sunlight, humidity, etc.).
These conditions will determine how fast the hygroscopic
discs will dry out, and since the landscape will also be
experiencing the same conditions, the irrespective drying
rates will roughly parallel each other. Note that there is
an adjustment capability on the rain sensor that will slow
down the reset rate. By turning the “ventring” (See Figure
4) to completely or partially cover the ventilation holes, the hygroscopic discs will dry more slowly. This adjustment
can compensate for an “overly sunny” installation location or peculiar soil conditions. Experimenting with the vent
ring will best determine the ideal vent setting.
Extension needed:
then use:
25-50 ft.
20 AWG
50-100 ft.
18 AWG
100 ft. or more
16 AWG
A
B
C
D
E
F
A Cap
B Vent Ring
C Ventalation Holes
D Housing
E Mounting Bracket
F 24 VAC Wire to Controller
FIGURE 1: Mounting Rain Sensor
FIGURE 3: Wiring
FIGURE 2: Wiring
FIGURE 4: Parts Diagram
Timer - Controller
Line-In
Common Wire
to All Valves
Line-Out
(on Pump)
Pump
Start
Relay
Solenoid Valves
Rain Sensor
Timer - Controller
Common Wire
to All Valves
Solenoid Valves
Rain Sensor
Timer - Controller
Line-In
Common Wire
to All Valves
Line-Out
(on Pump)
Pump
Start
Relay
Solenoid Valves
Rain Sensor
Timer - Controller
Common Wire
to All Valves
Solenoid Valves
Rain Sensor
Timer - Controller
Line-In
Common Wire
to All Valves
Line-Out
(on Pump)
Pump
Start
Relay
Solenoid Valves
Rain Sensor
Timer - Controller
Common Wire
to All Valves
Solenoid Valves
Rain Sensor
