Haier HSU12XHK, Service Manual, Page: 15 / 71

HSU09/12XHK-SM Functions and Control
Domestic Air Conditioner
12
5.1.5 Heat in g mode:
*Temperature control range : 60°F ---86°F
*Temperature control precision: 2°F
*Control Character:
When Tr ≤ Ts, compressor, four-ways valve and outdoor fan motor is on, indoor fan motor runs as in cold
, and 7°F of compensation is added after compressor is started.
When Tr>Ts+9°F, compressor is off, and the indoor fan motor runs as in warm blast mode.
When Tr<Ts+9°F, compressor, four-ways valve and outdoor fan motor is on, and the indoor fan motor
runs as in cold .
*Control of indoor fan motor:
Manual operation: The wind speed can be set to high, medium, low or automatic as required.
Automatic operation: When Tr < Ts, the wind speed is high;
When Ts ≤ Tr≤ Ts+3°F, the wind speed is medium.
When Ts+3°F ≤ Tr, the wind speed is low.
*Control of air door: setting the position of air door as required.
*Compressor control 喚 The compressor can’t be controlled by temperature sensor in 2 minutes after start
up and also can’t be started again at least 3 minutes later after shut down. There are 3-minute protection with
power on for the first time (over 3 minutes with power off). The compressor must be started again 3 minutes
later after shut down.
*Avoiding electrical shock: outlet air is available 2 seconds later after start up.
*Timer on, Timer off and sleep control are available.
*Control of 4-way valve: When the unit is started for the first time, the 4-way valve starts runnig 10
seconds earlier than compressor does. After compressor stops runnig, the 4-way valve continues running for
2 minutes and then stops. If changing the unit from heating to cooling, the 4-way valve is shut off 2 minutes
later and compressor is started 3 minutes later.
5.1.5.1 Cold draf t pr evetion:
5.1.5.1.1 Compressor is interrupted during the defrosting operation and continues to run after
defrosting is completed. When the indoor exchanging temperature is below 73°F, the indoor fan motor is off.
When the indoor exchanging temperature is above 73°F, the indoor fan motor is running at weak speed.
5.1.5.1.2 If the temperature of coil pipe can’t be above 100°F 4 minutes later after start up, fan motor
is running at the preset wind speed.
5.1.5.1.3 If the temperature of coil pipe is above 100°F 4 minutes later after start up, fan motor is
running at the preset wind speed.
5.1.5.1.4 If coil pipe descends to the temp. lower than 100°F from 100°F. fan motor is running at the
preset wind speed.
*Warm blast: If the temperature sensor is off. Compressor stops runnig. If the temperature of coil pipe is
above 73°F, fan motor enter breeze mode; and if the temperature of coil pipe is below 68°F, fan motor stops
running.
5.1.5.2 High temperatur e prote ction and high temperature expiration protection:
5.1.5.2.1 High temperature prevention: When the temp. of coil pipe is above 132°F, the outdoor fan
motor stops.When the temp descends to 125°F, the outdoor fan motor is restarted ,fan should keep stopping
more than 45 seconds.
5.1.5.2.2 High temperature expiration prevention:When the temp.of coil pipe is above 143°F,compressor
and outlet air stop running 10 seconds later, and inlet air runs as the temp. sensor is off. When compressor
stands by for 3 minute and the temp. of coil pipe is below 122°F, the unit can be started again.