Flooded type water cooled screw chiller (PCB Control)
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fault happens. Fault on screen must be confirmed and cleared manually; when both temperature
and time condition gets satisfied, the chiller can restart.
When suction pressure is lower than the protective low pressure set point (effective for time delay),
stop according to abnormal shutdown program. After the switch reset, fault on screen must be
confirmed and cleared manually; when both temperature and time condition gets satisfied, the
chiller can restart.
Anti-freeze protection
Over low leaving chilled water temperature
When leaving chilled water temperature gets lower than 4°C, perform low water temperature
protection and stop according to abnormal protective shutdown program. Cooling water
pump/chilled water pump/cooling tower fan keeps on running. When leaving chilled water
temperature gets higher than 10°C, unit resets. When both temperature and time condition gets
satisfied, the chiller can restart.
Mechanical antifreeze switch
The switch trips when leaving chilled water temperature <= 3°C and chiller stops according to
abnormal protective shutdown program. Reset at 10°C and fault on screen must be cleared
manually; when both temperature and time condition gets satisfied, the chiller can restart.
Compressor motor protection
Alarm when compressor protection module trips. Perform abnormal protective shutdown program
immediately. Fault on screen must be confirmed and cleared manually; when both temperature and
time condition gets satisfied, the chiller can restart.
Compressor overload protection
Thermal overload relay trips when heat storage reaches trip point. Faulted compressor will stop
immediately to abnormal protective shutdown program and other normal system will keep on
running. After the switch reset, fault on screen must be confirmed and cleared manually; when both
temperature and time condition gets satisfied, the chiller can restart.
Oil level protection
During unit running, if oil level keeps on lower than set point for 30s, the unit will stop immediately
according to abnormal protective shutdown program. After the switch reset, fault on screen must be
confirmed and cleared manually; when both temperature and time condition gets satisfied, the
chiller can restart
High cooling leaving water temperature protection
When leaving cooling water temp. is higher than 45°C during unit operating, the chiller will stop
immediately according to abnormal protective shutdown program. Reset at 38°C and it needs to be
confirmed and cleared manually; when both temperature and time condition gets satisfied, the
chiller can restart.
