Gree TERRA09HP230V1A Installation, Service & Troubleshooting page 18

System Operation 9,000/12,000 btuh Models, cont.
Basic Functions
3)Heating Mode
Heating Process
When the indoor ambient drops 20 F below the preset temperature, the unit will start the heating cycle. The outdoor fan,
compressor and 4-way valve will operate. The indoor fan will operate in the "Cold Air Prevention" mode in which the
indoor fan will have a 2 minute delay after the call for heating. The indoor evaporator coil temperature must reach 1040 F
before the indoor fan will start, this will prevent cold air from discharging from the indoor coil. When the indoor evapo-
rator coil temperature is > 1040 F, the indoor fan will operate at low speed for 1 minute. With 1 minute of operation or 2
minutes of no fan operation and the indoor evaporator coil temperature is > 1080 F, the indoor fan will operate at its preset
condition.
If the indoor ambient temperature is < 90 F and > 20 F of the preset temperature, the unit will run in its original mode of
operation.
If the compressor is running and the mode is changed from cooling to heating, the 4-way valve will be energized 2-3 min-
utes later.
If the indoor ambient temperature is >= 90 F than the preset temperature, the compressor will stop and the outdoor fan will
stop after a 30 second delay. The indoor fan will continue to operate at its preset mode.
The G10 technology will determine compressor frequency based on ambient temperatures.
18
Product Introduction
+90 F
+ 20 F
Stop heating