Haier 1U71S2SG1FA Service Manual page 218

Defrosting Operation Flow Chart:
Multi:
Fixed frequency
Compressor
Outdoor motor
4-way valve
All EEVs Auto open angle
All indoor motors ON
Frequency Control When Td is too High
Purpose: make compressor frequency control if the discharging temp. is too high, to lower the discharging temp.
efficiently and ensure the system can run normally.
Unitary:
118℃
115℃
112℃
109℃
105℃
95℃
Multi:
120℃
Beginning
Indicated FQY 60s Defrosting FQY 80 Hz （ E）
0HZ
5s
ON Send defrosting signal to indoor
OFF
ON
OFF
450-pulse
350-pulse(E)
OFF
If keeping for 10s, the unit stops, 3 minutes later, the unit can
re-startup. If in 60 minutesthe unit occurs alarm for 3 times, the
failure can be eliminated.
Reduce FQY rapidly 2HZ/S
Reduce FQY rapidly 1HZ/S
Reduce FQY slowly 1HZ/10S
Remain FQY
Increase FQY slowly 1HZ/10S
If keeping for 10s, the unit stops, 3 minutes later, the unit can
re-startup. If in 60 minutesthe unit occurs alarm for 3 times, the
failure can be eliminated.
end
60s
0HZ
450-pulse
Anti- cold air fun ction
215
Soft startup
Auto
15s
Auto open angle