Page 20 of 25
1) when the low pressure switch is detected to be open for a continuous 10 seconds, the unit will stop. When the
low pressure switch is detected to be closed, the unit will start (the compressor must meet the requirements of 3
minute delay).
2) when the low pressure switch is detected to be open for three times within one hour or for a continuous 30
minutes, the unit will enter the unit protection and display the corresponding fault code.
3) however, in the delay time (default is 5 minutes) of P16 after the compressor is started, and in defrost mode,
the system will not detect low pressure switch.
7.4 water flow switch protection
1) after the circulating pump runs for 60 seconds, the system starts to check the water flow switch status. If it is
detected to be disconnected for a continuous 5 seconds, the unit will shut down and enter the protection state,
displaying the fault. After 3 minutes, the unit exits the protection can be restarted;
2) if the protection occurs three times in 1 hour, the unit will be shut down and locked, displaying failure code.
7.5 linkage protection function of end switch (effective in heating/cooling mode)
When parameter A05 is set to
“1”, the end switch is invalid: the circulating pump starts and stops following the
compressor.
When parameter A05 is set to
“0”, the end switch is effective.
A. If the end switch is closed, the circulating pump is running continuously, and the compressor starts/stops
according to water temperature conditions.
B. If the end switch is open , both the circulating pump and the compressor will stop.
If the end switch is open, the unit stops and the "unit" symbol on the display flickers.
7.6 temperature difference protection for insufficient water flow
1) in cooling mode, after the circulating pump is started for 60 seconds, if inlet water temperature
– outlet water
temperature is
≥
B03 (default is 15
℃
) for a continuous 10 seconds, the unit will shut down and enter the protection
state, displaying the fault;
2) in the hot water / heating mode, after the circulating pump is started for 60 seconds, if outlet water temperature
- inlet water temperature is
≥
B03 for a continuous 10 seconds, the unit will stop and enter the protection state,
displaying the fault;
3) if there are three times of insufficient water flow temperature difference protection within one hour, the unit will
be shut down and locked, indicating failure.
7.7 outlet water over temperature protection
1) in hot water / heating mode, 60 seconds after the circulating pump is started, if the outlet water temperature is
≥
B04 (default is 70
℃
) for a continuous 5 seconds, the unit will stop. When the outlet water temperature is
≤
B04 - 10
℃
for a continuous 30 seconds, the unit will exit protection and can be started again;
2) if the protection occurs three times in 1 hour, the unit will stop and enter the protection state, displaying the
fault;
7.8 low outlet temperature protection
In cooling mode, 50 seconds after the circulating pump starts, if the outlet water temperature is
≤
B05 (default is
5
℃
) and lasts for 5 seconds, the unit will stop. When the outlet water temperature is
≥
B05 + 4
℃
and for a
continuous 30 seconds, the unit will exit protection and can be started again;
7.9 pipeline level I anti freezing protection
When the outlet water temperature or water inlet temperature is
≤
5
℃
for a continuous 10 seconds, the unit
enters the pipeline antifreeze protection. After the circulating pump runs for 1 minute, if the outlet water temperature is
≥
7
℃
for a continuous 10 seconds, the unit exits the pipeline level I antifreeze protection. Any unit failure does not
affect the antifreeze protection (except for the three-phase protection).
7.10 pipeline level II anti freezing protection (heating/cooling mode)