Gree GKH(12)BA-K3DNA1A/I, Service Manual

Page: 33 / 207

Super Free Match
Service Manual
CONTROL 29
2.2.4 Communication malfunction
Detection of the quantity of installed indoor units and BU modules: After 3min of energizing, if the outdoor
unit does not receive the communication data of certain indoor unit, the outdoor unit will judge that indoor unit is
not installed and will treat it as it is not installed. If the outdoor unit receives the communication data of that
indoor unit later, the outdoor unit will treat that unit as it is installed.
2.2.5 Compressor high-pressure protection
1) When the high-pressure switch is detected cut off for 3s continuously, the compressor will enter
high-pressure protection as it stops when reaching set temperature. Meanwhile, the outdoor unit will
send the signal of “high-pressure protection” to the indoor units;
2) After the appearance of high-pressure protection, the compressor can resume running only after cutting
off the power and then putting through the power.
2.2.6 Compressor low-pressure protection
1) Low Pressure Protection for Shutdown
a). After the compressor stops for five minutes, if it is detected that the low pressure protection is work, then
a low pressure protection signal will be send out.
b). If it is detected continuously for three seconds that the low pressure protection is work after the
compressor stops for less than five minutes, then a low pressure protection signal will be send out. However, if the
low pressure protection occurs twice in one hour, then it becomes unrecoverable and has to be recovered by
powering the outdoor unit again.
2) Low Pressure Protection during the Operation
a) When it is detected continuously for three seconds that the low pressure protection is work, then the whole
unit should be shut off and a low pressure protection signal should be sent to the indoor unit.
b) On condition that a low pressure protection error occurs and the whole unit has stopped for more than
three minutes and it is detected continuously for six seconds that the low pressure protection switch is closed, then
this error can be eliminated. However, if the low pressure protection occurs twice in one hour, then it has to
eliminate the error by powering the outdoor unit again.
2.2.7 Compressor overload protection
If the compressor overload switch is detected having movement, the indoor unit will display the
corresponding malfunction as it stops when the indoor temperature reaching set temperature. When the
compressor stops for more than 3min and the compressor overload switch is reset, the unit will resume operation
status automatically. If the protection appears for more than 6 times (if the running time of the compressor is
longer than 30min, the protection times record will be cleared), the unit can not resume operation status
automatically, but can resume running only after cutting off the power and then putting through the power.
2.3 Other function
2.3.1 Refrigerant Recovery
The refrigerant can be recovered from the outdoor unit. When the unit is powered on and runs under the
COOL mode, it is available within five minute to go the refrigerant recovery mode by operate the testing board of
the outdoor unit with “Fo” displayed.
2.3.2 How to quit the refrigerant recovery:
When the refrigerant recovery has started, it will quit by operate the testing board of the outdoor unit or the
power is cut off.