Control for hot water circulating pump - has sensors for input temperature and input pressure to pump and with microprocessor control to prevent cavitation

摘要

The hot water system has a circulating pump (1) to move the water between the reservoir and the system. The inlet (2) of the pump has monitors for temperature and pressure. The values are digitised and processed by a microprocessor to generate control signals for the pump. If the pressure/temperature values fall outside programmed levels then the pump is stopped and an alarm operated. The system detects the onset of cavitation and prevents the pump from operating below its programmed level. The minimum inlet pressure for the pump, corresponding to particular temperature provides a reference value for the control. ADVANTAGE - Improved protection for circulating pump, failsafe operation of closed heating system.