York YHKJXH012BAM--FX Service Manual page 109

3.8.2 Procedure
Cooling mode: refer to "the oil return procedure in cooling mode"
Heating mode: refer to "the oil return procedure in heating mode"
3.8.3 The protection treatment in oil return operation:
In the course of cooling oil return, because of all kinds of protection or abnormal unit stop,
after the unit restart, the time will not be cleared, the system need another oil return operation.
In the refrigerant flow course in oil return of cooling mode or after oil return, and within 5
minutes after the refrigerant being eliminated is over, the anti-freeze protection and low
pressure protection are invalid, other protection is valid.
In the course of heating oil return ,because of all kinds of protection or abnormal unit stop, the
system need not another oil return operation after the unit stop for 3 minutes and enter in
heating mode directly. In the course of changing to cooling oil return, the anti-freeze
protection and low pressure protection are invalid, other protection is valid.
Oil return procedure in cooling mode:
Send oil return signal
Inverter compressor
outdoor unit PMV auto open angle
Outdoor fan motor auto operation
running indoor motor auto operation
stop indoor motor
4-way valve
Quit condition of oil return:
OR
Oil return procedure in heating mode:
oil return beginning
60 秒
80 Hz（E）
auto FQY
auto（TC or ambient control）
auto（set fan speed）
stop
OFF
1 minute later after oil return is over
＆
OR
Max. 10 minutes
300pulse（E）
stop
OFF
Td‐Tcm＞30℃
Ts‐Tc＞30℃
Tc＜‐35℃
109
oil return over
ref.eliminated 30s
40HZ（E）
auto open angle
120pulse（E）
auto operation
auto operation
stop
OFF