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1.7 Discharge Regulating Valve
It is essential to fit a regulating valve on the discharge of the filter for two reasons:
1. To ensure the correct flow rate through the filter, and
2. to provide the necessary head pressure on the filter’s discharge for efficient
backwashing.
1.8 Control System
The control system is located directly beneath the control cover, which is held in place by
two snug fitting “O” rings. The power supply to the circuit board is 24 VDC with a maximum
load of 1 Amp.
The following indicators and controls are provided:
1.8.1 Control Cover
1. Power LED – Illuminates AMBER
when the panel is connected to a live
24 VDC supply.
2. Backwash LED – Illuminates BLUE
when the filter is in backwash
mode.
3. Fault LED – Illuminates when there
is a fault with the filter. For various
faults and indications, refer to
section 2.4.
4. Manual Backwash Button (Hand
Symbol) - Used to manually initiate
a backwash.
5. Backwash Counter - A non-reset
counter which is incremented at the
completion of each backwash.
1.8.2 Circuit Board
Fitted to the vertical circuit board are the following (please refer to Exhibit 2 for a layout
drawing of the board):
a. Backwash Duration Timer (marked WASH) - This timer is used to set the amount of time
that the diverting valve remains stationary at each pod during backwash. Thereby,
controlling the amount of water used to backwash each pod. There are six set-points
beginning at two seconds and increasing by one second to the maximum setting of 7
seconds, please refer to Section 2.2.
