Gree GWH18MC-K3DNA2G Service Manual page 34

Service Manual
extend 1 minute, the outer fans will stop (During the period in the 1 minute, the air flow of outer fans can be changed according to the
outdoor ambient temperature changes); When running with force, the outdoor fans shall run in the highest air flow.
(3) 4-way valve control
1. The 4-way valve control under the modes of Cooling, dehumidification and supplying air: closing;
2. The status of 4-way valve control under the heating mode: getting power;
(1) 4-way valve power control under heating mode
a. Starts the machine under heating mode, the 4-way valve will get power immediately.
(2) 4-way valve power turn-off control under heating mode
a. When you should turn off the power or switch to other mode under heating mode, the power of 4-way valve will be cut after 2 minutes
of the compressor stopped.
b. When all kinds of protection stops, the power of 4-way valve will be cut after delaying 4 minutes.
(3) Defrosting control under heating mode:
a. Defrosting begins: The power of 4-way valve will be cut after 50s of entering into the defrosting compressor.
b. Defrosting stops: The 4-way valve will get power after 50s of exiting the defrosting compressor.
(4) Evaporator frozen-preventing protection function
At the mode of Cooling, dehumidifying:
Evaporator frozen-preventing protection function is allowed to begin after 6 min of starting the compressor.
1. Starting estimation:
After the compressor stopped working for 180s, if T
machine is only allowed to start for operating, otherwise it should not be started, and should be stopped to treat according to the frozen-
preventing protection: Clear the trouble under the mode of power turn-off / heating, and the protection times are not counted.
2. Frequency limited
[T
frozen-preventing normal speed frequency-reducing temperature
compressor.
3. Reducing frequency at normal speed:
If [T
frozen-preventing high speed frequency-reducing temperature
frequency by reducing 8Hz/90s till the lower limit;
4. Reducing frequency at high speed:
If [T
frozen-preventing power turn-off temperature
reducing 30Hz/90s till the lower limit;
5. Power turn-off:
If the T <[T
inner pipe frozen-preventing power turn-off temperature
] <T , and the compressor has stopped working for 3 minutes, the whole machine should be allowed to operate.
temperature inner pipe
6. If the frozen-preventing protection power turn-off continuously occurs for six times, it should not be resumed automatically, and you
should press the ON/OFF button to resume if the fault keeps on. During the process of running, if the running time of compressor exceeds
the t evaporator frozen-preventing protection times zero clearing time , the times of frozen-preventing power turn-off should be cleared to
recount. The mode of stopping the machine or transferring to supply air will clear the trouble times immediately (if the trouble can not be
resumed, mode transferring will not clear it).
(5) Overload protection function
Overload protection function at the mode of Cooling and dehumidifying
1. Starting estimation:
After the compressor stopped working for 180s, if T
machine is allowed to start, otherwise it should not be started, and should be stopped to treat according to the overload protection: Clear
the trouble at the mode of power turn-off / heating, and the protection times are not counted.
2. Frequency limited
If [T
Cooling overload frequency-limited temperature
compressor.
3. Reducing frequency at normal speed and power turn-off:
If [T
Cooling overload frequency reducing temperature at high speed
frequency by reducing 8Hz/90s till the lower limit; After it was running 90s at the lower limit, if [T
]≤T , then Cooling overload protects machine stopping;
speed outer pipe
Technical Information
> [T
inner pipe
] ≤T [T
inner pipe frozen-preventing frequency-limited temperature
] ≤T [T
inner pipe frozen-preventing normal speed frequency-reducing temperature
] ≤T [T
inner pipe frozen-preventing high speed frequency-reducing temperature
], then frozen-preventing protect to stop the machine; If T[
<[T
outer pipe
] ≤[T
outer pipe T Cooling overload frequency reducing temperature at normal speed
] ≤T
outer pipe
frozen-preventing frequency-limited temperature
] you should adjust the compressor frequency by
Cooling overload frequency-limited temperature
< [T
Cooling overload power turn-off temperature
(the temperature of hysteresis is 2 )], the
] , you should limit the frequency raising of
], you should adjust the compressor
frozen-preventing frequency-limited
] (the temperature of hysteresis is 2ºC ), the
], you should limit the frequency raising of
] , you should adjust the compressor
Cooling overload frequency reducing temperature at normal
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