Haier HDU-60CA03T3 Service Manual page 29

Commercial Air Conditioner
In heating mode, after in sleep mode for 1 hour, set temperature will reduce 2℃, after a second 1
hour, set temperature will reduce a second 2℃, and after continue working for 3 hours, set
temperature will arise 1 ℃, and continue working 3 hours, the unit shut off.
Sleep sketch map in heating mode
℃
Ts
Ts-2
Ts-3
Ts-4
1 2 5 8
2.8 Compulsory cooling operation
When received the compulsory cooling signal from operation panel, the main unit will run for 5
minutes at indoor and outdoor fan motor in high speed, in cooling mode (that is compressor running
5 minutes) and send this signal to outdoor. Within 5 minutes, the system will not adjust any
protection, and not affected by ambient temperature. But the compressor will be protected by 3
minutes protection function, and after 5 minutes, it will turn to normal cooling mode. In compulsory
cooling mode, the crank heater, negative ion, fresh air function will stop completely.
2.9 Water level and drainage control
a. In cooling (including automatic cooling mode and cooling by emergency switch) and
dehumidifying modes, the water pump works if the compressor runs otherwise it will stop 5 minutes
later after the compressor stops.
b. In heating and blowing mode, when water tank is fully filled, the float switch will be off. The water
pump will start to work after a controller has detected this signal and has last for 2 seconds. it will
continue working for 5 minutes after the float restores to normal state.
c. If the full water signal is detected continuously over 5 minutes, the water pump indicator will flash
to alarm and compressor stops running. The water pump will run 5 minutes, then pause for 5
seconds before next 5 minutes' running, ... until the float restores to normal state, after which the
pump will run for 5 minutes then stop.
2.10 Negative ion and high voltage collecting dirt function
When there is health setting signal, and indoor fan motor running, gate switch close, negative
ion/high voltage collecting dirt function will work.
2.11 Fresh air function
When there is fresh air signal, there will be fresh air output signal. In any mode of ON/OFF state,
there always is fresh air output (controlled by the fresh air signal from the operation panel, not
limited by the ON/OFF signal from operation panel). Fresh air function includes continuous and
auto types:
a. Continuous: as soon as there is fresh air signal, it will be in fresh air mode all along unless
receive the stop signal to stop fresh air function.
b. Auto: Fresh air be on for 20 minutes, and off for 20 minutes. Repeat in this way unless receive
the stop signal to stop fresh air function.
2.12 pressure protection
After compressor is running for 3 minutes, the unit will check the pipe pressure, when the pipe
pressure is too low and low pressure switch is running for 30 senconds, compressor and outdoor
fan motor will stop and will send failure, then compressor will not start up again; when being
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