Properly perform the sequence of opening and closing of the high and low temperature refrigeration cycle pump group to ensure normal operation after the host is started. Note that the condenser heats up well, otherwise the high temperature protection device of the high and low temperature refrigeration cycle pump group will stop and even cause malfunction due to the condensing temperature and the corresponding condensing pressure being too high. The cold water in the evaporator should be circulated, otherwise the cold water temperature will be low, the cold water temperature protection device will stop, or the low temperature protection device will stop due to the evaporation temperature and the corresponding evaporation pressure being too low, even leading to the evaporator. Cold water freezes and damages equipment.

Therefore, the boot sequence is: (must be strictly observed) Cooling tower fan on → cooling water pump on → cold water pump on → high and low temperature refrigeration cycle pump group. The shutdown sequence of the high and low temperature refrigeration circulating pump set is: (must be strictly observed) The equipment group stops → the cooling tower fan stops → the cooling water pump stops → the cold water pump stops. When the machine is shut down, the equipment group should be shut down half an hour before leaving work. The cold water pump is shut down after work, which is conducive to saving energy, avoiding downtime and protecting the unit. Before running the high and low temperature refrigeration cycle pump refrigeration cycle, make sure that the heating cycle pipe valves are all closed.

Maintenance of high and low temperature refrigeration circulating pumps is indispensable. At the same time, the operator needs to have certain operational knowledge of the equipment and will not find operational faults.