Gree TERRA09HP230V1A Installation, Service & Troubleshooting page 32

System Operation 18,000/24,000 btuh Models, cont.
Basic Functions
Defrost Process, cont.
2) When heating has operated continuously for 45 minutes, or accumulated for 90 minutes, the unit will enter defrost
mode in 3 minutes after meeting any of the conditions below:
A. Outdoor ambient >= 410 F and outdoor coil <= 280 F
B. 280 F <= T ambient< 410 F, T
outdoor
C. 230 F <= T ambient < 280 F <= T
outdoor
D. 140 F <= T ambient < 230 F , T
outdoor
3) During defrost, if run time for the compressor does not reach 3 minutes, the defrost cycle will not start for the next 2
hours. At that time the compressor stops operation and 30 seconds later the outdoor fan will stop. 30 seconds after this
the 4-way reversing valve will de-energized. Following another 30 second delay, the compressor will increase its speed for
defrosting. Defrosting will last for 450 seconds or until the T
decrease it's speed for 30 seconds, then will stop. In another 30 seconds the 4-way valve will energize, the 60 seconds later
the compressor and outdoor fan will start. The compressor speed for defrosting will be 85hz.
During Defrost mode, a H1 will be displayed on the indoor front panel display indicating the user selected mode has been
overridden and the system is performing an outdoor coil defrost operation.
System Protection
Cold Air Prevention (Heating mode with compressor running)
The system guards against discharging cold air in heating mode. It will delay the indoor fan until the evaporator coil has
warmed up to discharge warm, comfortable air into the room.
1) When the T ambient < 750 F and the T
indoor
to run at low speed after a 2 minute delay. This will reduce cold air upon heating startup. Within 2 minutes, if
T tube > 1040 F, the indoor fan will run at low speed. After 1 minute of operation, the fan will run at the preset fan
indoor
mode. Within 1 minute of low speed operation or 2 minutes of no fan operation, with the T
run at the preset mode.
2) If the T ambient >= 750 F and the T
indoor
at the preset mode. After 1 minute of low speed operation, if the and the T
preset mode.
Note:
The T ambient in 1 & 2 above refers to the unit going into the heating mode, coming out of defrost.
indoor
Overcurrent and Speed Protection (
The software will monitor the compressor current draw and adjust the compressor speed in order to maintain the inverter and
compressor in a safety and reliable operating range.
A. If I <= 13, an increase or decrease in frequency will be allowed
total
B. If I >13 and < 17, frequency will remain the same
total
C. If I >= 17, the compressor will stop and the indoor fan will stop after 30 seconds
total
4)Fan Mode
Under this mode, the fan will run at the preset speed and the outdoor fan, compressor and 4-way valve will stop.
32
Product Introduction
tube <= 210 F
outdoor
tube <= 180 F
outdoor
tube -T
outdoor compensation
outdoor
tube <= 1040 F with the fan in a stopped state, the indoor fan will begin
indoor
tube <= 1080 F the indoor fan will run at low speed for 1 minute than run
indoor
Total Current = I )
total
<= (T ambient - 370 F)
outdoor
tube >= 500 F, at this temperature the compressor will
tube > 1080 F the fan will operate at its
indoor
tube > 1080 F, the fan will
indoor