Heating Mode - Gree U-MATCH GUHD09NK3CO Service Manual

A/A DC INVERTER U-MATCH AIR CONDITIONERS

2.3 Heating Mode

OFF
compressor
OFF
outdoor fan
EXV
4-way valve
Indoor fan OFF
(cooling)
3s
send out heating
command
capacity
demand ＞0
When the heating command is sent out, it is started to calculate the system load demand value. If the load is 0,
all the loads will not be put into operation. If the load is >0, the EXV will be firstly opened to step Y; then the outdoor
fan is started. After 30 seconds, the compressor will increase its frequency to the required initial frequency 40Hz
before it started. It is started to count the time when the compressor frequency is increased to 20Hz. After 10
seconds, the 4-way valve is energized and then the indoor fan will run as per cold air prevention mode. The
compressor will keep running at initial frequency for 3 minutes. After that, the compressor, EXV and outdoor fan will
adjust according to logic.
Heating mode
3min
ON
Acc.to controll
logic
Acc.to controll
ON
30s
Xsteps
ON
10s
OFF
Run as per cold air
prevention mode
Send out switch-off command
logic
60s
150s atfer the compressor is stoped
150s
Firstly switch off to step 0 and
then switch off step 60
120s
Blow residual heats
CONTROL
27