Panasonic Urban Multi MX1R Series Service Manual page 455

Outline of Control
3.1.10 Oil Return Operation
Activates the oil return operation to collect refrigerant oil from the field pipes when the following conditions
are met.
[Start conditions]
1. When cumulative compressor operating time from power ON exceeds 2 hours
2. When cumulative compressor operating time from completion of previous return operation exceeds 8
∗ 1) When defrost control operation for more than 4 minutes with inverter compressor frequency of "A"Hz or
2) When condition 1. or 2. is satisfied during heating operation, the electric heaters of indoor units are
3) The oil return operation is not activated for 28 minutes after the completion of the previous defrosting
[Oil return operation]
„ The compressor operating frequency is set to "B" Hz shown in the following table.
[Ending conditions]
„ The oil return operation ends after 1~8 minutes of operation. However, when the compressor stop
PA-16MA1XPK
PA-18MA1XPK
PA-20MA1XPK
PA-24MA1XPK
PA-26·28·30MA1XPK
434
hours.
However, when the upper-limit frequency is limited to less than "A" Hz during the previous oil return
operation, the above time period of 8 hours is changed to 4 hours.
higher, oil return time reset to 8 hours.
turned off 2 minutes prior in order to prepare for the oil return operation.
operation.
conditions are met during an oil return operation, the compressor stops after the completion of the oil
return operation.
When the compressor stops during an oil return preparation operation, the oil return operation is
activated at the next startup.
INV
33Hz
41Hz
41Hz
75Hz
75Hz
A
STD1 STD2 INV
ON — 52Hz
ON — 71Hz
ON — 71Hz
ON OFF 52Hz
ON OFF 52Hz
Function UM Combination "MA1R Series" Using R-407C
PACD011001C2
B
STD1 STD2
ON —
ON —
ON —
ON ON
ON ON