The backwash waste pumps are controlled by a four-float level control system. Existing mixers are controlled by an existing control panel. A new ultrasonic level transducer provides basin level indication at the PCS. A new high-level switch generates a HIGH level ALARM at the PCS.
Local Control:
The pumps and mixers will continue to be controlled by the existing local control panels without changes in operation.
PLC / HMI Configuration:
- Status Display:
- Wet well level indication.
- Ultrasonic transducer FAIL.
- Operator Entries:
- Basin level alarm setpoints (HIGH-HIGH, HIGH, LOW, LOW-LOW).
- Alarms:
- Basin level ALARM (HIGH-HIGH, HIGH, LOW, LOW-LOW).
- Pump discharge pressure ALARM (HIGH-HIGH, HIGH, LOW, LOW-LOW).
- Backwash water flow ALARM (HIGH-HIGH, HIGH, LOW, LOW-LOW).
- Backwash vent valve FAULT.
- Historical Trending:
- Backwash pump station level.
- Backwash water flow.
- Pump discharge pressure.
- Pump running (each).