This diagram details how to use an external sensor, such
as a temperature sensor, to activate the pre-set program on
an RC Series controller. The sensor starts will be in addition
to the normal program.
How Does It Work
Normal program starts are done when both the Day and Hour
micro-switches are activated. By using a relay to bypass these
switches, a program may be initiated. The normally open contacts
of a relay are connected to the controller micro-switches
as shown in the drawing. When the relay is energized, the
voltage is routed from the Day micro-switch to the hour micro-switch,
which causes the controller to start its program.
Necessary Equipment
The relay specifications will vary depending on the type
of sensor used. Be sure to match the coil voltage to the output
of the sensor. The load on the contacts is about .25 amps
at 24 VAC.
Programming
The controller should be properly programmed for the area
being watered. The controller will continue to operate using
the programmed start times and days.
The controller will continue to run as long as the sensor
has energized the relay.
