Sequence of Operation for Chilled Water Pumps

Inputs:

• Chilled water supply temperature sensor
• Chilled water return temperature sensor
• Flow rate sensor
• Pressure sensor
• Pump status switches

Outputs:

• Pump motor control relay
• Alarm and fault signal outputs

Control sequence:

1. The controller reads the input signals from the chilled water supply and return temperature sensors to determine the current operating conditions in the system.
2. If the chilled water supply temperature is above the desired setpoint and the flow rate and pressure are within acceptable limits, the controller turns on the chilled water pump and begins pumping.
3. If the chilled water supply temperature is below the desired setpoint, the controller turns off the pump to avoid overcooling.
4. If the flow rate drops below a certain setpoint or the pressure drops below a setpoint, the controller increases the speed of the chilled water pump motor to increase flow and pressure.
5. The controller monitors the status of the chilled water pump and triggers alarms or fault signals if any issues are detected.
6. If multiple chilled water pumps are used in the system, the controller may adjust the number of pumps running based on the load and operating conditions.
7. The controller also monitors the power consumption of the chilled water pump motor to ensure energy efficiency.