Haier FlexFit Pro Series Service Manual page 106

2. Defrosting end contition:
After defrosting condition starts, it will last no more than 10 minutes (E) . Using Te to test outdoor heat exchanger
frosting condition, if it lasts over accumulative 60 seconds of 7°C (E) or over accumulative 30 seconds of 12°C (E)
or over 15°C (E) , defrosting will stop.
3. Forced defrost:
Starting condition of forced defrosting: in heating operation (including standby state) , unit will start forced
defrosting after receiving forced defrosting signal by indoor.
Indoor manual defrosting signal will keep until outdoor enters defrosting.
Note:
It can enter manual defrosting when compressor in OFF state, but it needs to follow 3-minute protection
rule.
4. Timing defrosting mode condition:
Starting condition: after setting outdoor function dip switch, it will execute timing defrosting in heating mode.
A. If outdoor ambient temp is over 10 degree (E) , even if timing defrosting is set, it will follow the auto defrosting
condition, meaning auto entering and auto quitting.
B. When outdoor ambient temp is lower than 10 degree (E) (including 10 degree ) , it will follow the defrosting
operation as below:
When compressor runs for continuous 10 minutes (E) and runs for accumulative 50 minutes (E) , it will enter
defrosting operation.
C. Timing defrosting operation and quit condition is the same as auto defrosting.
6.2.8 Four way valve control:
1. When powering on, four way valve is in OFF state.
2. In other modes except heating, the four way valve is powered off.
3. The 4-way valve is on in the heating mode, except under the following conditions:
1) in heating mode, in initial starting time of compressor to ensure the pressure difference ;
1) in defrosting operation:
a, if there is no compressor stopping, power four way valve off;
4. When shifting from heating to other modes, four way valve will power off after a while.
5. 4-way valve protection:
In heating mode, after continuous running of compressor for 10 minutes, if Tm (indoor sensor) < indoor ambient
temp -2°C (E) and Te (outdoor sensor) >15°C (E) for continuously for 1 minute, four way valve will be powered
off, reporting four way valve error. If the compressor starts after 3 minutes and the error is detected 3 times
continuously in 1 hour, a 4-way valve error code will be displayed. The error will not be detected during defrost
and within 10 minutes after termination of defrost, in the oil return mode, or within 10 minutes following an oil return
cycle.
6. Only in initial starting of compressor in heating mode, outdoor fan motor and four way valve will powering on
simultaneously.
7. If compressor frequency is higher than regulated frequency before off, it will lower to required frequency and then
stop.
8. Compressor inverter frequency and outdoor fan speed will operate in accordance with other requirement.
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FlexFit Pro