Gree GWH12MB-K3DNE3G Service Manual page 21

Service Manual
② Protection
a. In cooling operation, protection is the same as that under the cooling mode;
b. In heating operation, protection is the same as that under the heating mode;
c. When ambient temperature changes, operation mode will be converted preferentially. Once started, the compressor will
remain unchanged for at least 6 minutes.
(6) Common Protection Functions and Fault Display under COOL, HEAT, DRY and AUTO Modes
① Overload protection
T tube: measured temperature of outdoor heat exchanger under cooling mode; and measured temperature of indoor heat exchanger
under heating mode.
1) Cooling overload
a. If T tube≤52°C, the unit will return to its original operation state.
b. If T tube≥55°C, frequency rise is not allowed.
c. If T tube≥58°C, the compressor will run at reduced frequency.
d. If T tube≥62°C, the compressor will stop and the indoor fan will run at preset speed.
2) Heating overload
a. If T tube≤50°C, the unit will return to its original operation state.
b. If T tube≥53°C, frequency rise is not allowed.
c. If T tube≥56°C, the compressor will run at reduced frequency.
d. If T tube≥60°C, the compressor will stop and the indoor fan will blow residue heat and then stop.
② Exhaust temperature protection of compressor
If exhaust temperature ≥98°C, frequency is not allowed to rise.
If exhaust temperature ≥103°C, the compressor will run at reduced frequency.
If exhaust temperature ≥110°C, the compressor will stop.
If exhaust temperature ≤90°C and the compressor has stayed at stop for at least 3 minutes, the compressor will resume its operation.
③ Communication fault
If the unit fails to receive correct signals for durative 3 minutes, communication fault can be justified and the whole system will stop.
④ Module protection
Under module protection mode, the compressor will stop. When the compressor remains at stop for at least 3 minutes, the
compressor will resume its operation. If module protection occurs six times in succession, the compressor will not be started again.
⑤ Overload protection
If temperature sensed by the overload sensor is over 115°C, the compressor will stop and the outdoor fan will stop with a time lag of
30 seconds. If temperature is below 95°C, the overload protection will be relieved°C.
⑥ DC bus voltage protection
If voltage on the DC bus is below 150V or over 420V, the compressor will stop and the outdoor fan will stop with a time lag of 30
seconds. When voltage on the DC bus returns to its normal value and the compressor has stayed at stop for at least 3 minutes, the
compressor will resume its operation.
⑦ Faults of temperature sensors
3. Other Controls
(1) ON/OFF
Press the remote button ON/OFF: the on-off state will be changed once each time you press the button.
(2) Mode Selection
Press the remote button MODE, then select and show in the following ways: AUTO, COOL, DRY, FAN, HEAT, AUTO.
(3) Temperature Setting Option Button
Each time you press the remote button TEMP+ or TEMP-, the setting temperature will be up or down by 1°C. Regulating
Range: 16~30°C, the button is useless under the AUTO mode.
(4) Time Switch
You should start and stop the machine according to the setting time by remote control.
(5) SLEEP State Control
1. In cooling mode:
1.1 When the initial set temperature is 16-23°C,the temperature will rise 1°C by every hour after sleep function is set; the temperature
will not change after rising 3°C; after running for 7 hours, the temperature will decrease 1°C and it will not change after that.
Technical Information
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