TM 10-4610-310-14
0004 00
CONTROL MODULE continued
Programmable Logic Controller
The PLC is responsible for the essential functions of the LWP. It controls the valves on the UF module for
automated backwash and fast flush cycles; controls the 3-way air solenoid valve on the diesel engine air shutoff
assembly to shutdown the engine in case of emergencies such as low level in the filtrate tank, high-pressure in
the RO system etc. It also controls the chemical pumps: If the pressure in the RO product line exceeds the limit
and the low-pressure switch is tripped, it shuts down the hypochlorite pump and antiscalant pump. If the raw
water pump is not running, the coagulant pump is shut down.
The PLC monitors the operating parameters through the level switch, low and high pressure switches etc.
See Figure 6.
INPUTS (24)
LED
CONTROL INDICATORS
OUTPUTS (16)
Figure 6. Programmable Logic Controller Controls and Indicators.
NOTE
For a complete listing of inputs and outputs on the PLC see WP 0068 00.
