York YH9FXH12BAH FX Series Service Manual page 17

When all the ranges alternate, there is ±1 difference.
7.1.5 Heating mode:
*Temperature control range : 16 —30
*Temperature control precision: 1
*Control Character:
When Tr Ts, compressor, four-ways valve and outdoor fan motor is on, indoor fan motor runs as in cold blast
mode, and 4 of compensation is added after compressor is started.
When Tr Ts+5 , compressor is off, and the indoor fan motor runs as in warm blast mode.
When Tr Ts+5 , compressor, four-ways valve and outdoor fan motor is on, and the indoor fan motor runs as in
the mode of avoiding cold blast.
*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;
*Control of air door: setting the position of air door as required.
*Compressor control 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 running 10 seconds earlier
than compressor does. After compressor stops running, 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 .
7.1.5.1 Cold draft prevention:
7.1.5.1.1 Compressor is interrupted during the defrosting operation and continues to run after defrosting is
completed. When the indoor exchanging temperature is below 23 , the indoor fan motor is off. When the indoor
exchanging temperature is above 23 , the indoor fan motor is running at weak speed.
7.1.5.1.2 If the temperature of coil pipe can't be above 38
the preset wind speed.
7.1.5.1.3 If the temperature of coil pipe is above 38
preset wind speed.
7.1.5.1.4 If coil pipe descends to the temp. lower than 38
speed.
*Warm blast: If the temperature sensor is off. Compressor stops running. If the temperature of coil pipe is above
State2
State3
Ts-1
Ts
(cooling only have no the mode)
When Ts Tr Ts+2 , the wind speed is medium.
When Ts+2 Tr, the wind speed is low.
State1
Ts+2
Ts+2
4 minutes later after start up, fan motor is running at
4 minutes later after start up, fan motor is running at the
from 38 . fan motor is running at the preset wind
15
Functions and control