Figure 2-73. Solid-State Timer (Pilot Control Valve)
Solid-State Timer. The solid state timer is approximately 8 inches high, 10 inches wide and 6 inches deep. Protruding
from the rear of the timer is the pilot controller and solenoid valve (fig. 2-70). Inside is a black RESET button and an
INTERNAL INDICATOR knob mounted to a subpanel (view 1, fig. 2-71).
Ensure INTERNAL INDICATOR knob is in the SERVICE position by pressing the black RESET button.
The INTERNAL INDICATOR knob allows the position of the pilot controller valve to be changed manually, which is never
necessary if timer is functioning properly. In any event, if pilot controller valve is not in SERVICE position, ROWPU cannot
be backwashed using normal procedures. In fact, ROWPU will not even operate.
Overcurrent protection is provided by an internal resettable semiconductor. In the event of an overload,
the circuit breaker is reset by depressing the RESET button. If power loss erases the memory of the time control counter,
an automatic homing circuit is incorporated into the system which returns the pilot controller to the service position
whenever power is restored.
Remove the subpanel to access the four 1 O-position rotary switches (view 2, fig. 2-74) used to set the
duration (in minutes) of each phase of the backwash cycle. Ensure settings are as follows: