Haier 1U71S2SG1FA Service Manual page 225

After oil return in cooling mode, the quit condition of refrigerant eliminated:
OR
Oil return procedure in heating mode:
Send oil return signal
Inverter compressor
indicated FQCY
Outdoor motor
4-way valve
All expansion valves
All indoors ON
Quit condition of oil return:
Max. 9 minutes (E)
OR
＆
1 minute later after oil return is over
Td Tc
＆
OR Ts Tc2AVE
‐
Tc2AVE＜ 35
Max. 10 minutes
oil return begins
60s
0HZ
5s
AUTO
ON
OFF
450pulse
auto angle
OFF
OR Td Tc＜20°C
‐
to count)
Ts Tc2AVE ＜15°C for 30s continuously(5 minutes later,
‐
begin to count)
Running for min. 5 minutes(E)
‐ ＞30°C
＞30°C
°C
‐
oil return FQCY
AUTO (TC control)
350pulse(E)
for 30s continuously(5 minutes later, begin
222
oil return over
60s soft startup
0HZ
AUTO
15s
450pulse
auto angle
anti-freezed startup