Special Operation - Fujitsu AUXB04GALH Service Manual

2-6 SPECIAL OPERATION

2-6-1 Oil Recovery Operation
(1) Purpose of the operation
The amount of refrigerant lubricant oil which has been transported to the indoor units
and the connection pipe with the refrigerant will become large as the operation time of compressor increases.
It is necessary to recover the oil back into the outdoor unit for a certain time interval
in order to prevent compressors from damaging due to lack of lubrication oil.
Cooling oil recovery operation
< Start condition >
Compressor accumulated operation time since last cooling oil recovery operation exceeds 3 hours
(first time : 1hour)
< End condition >
30 seconds have elapsed since the start and "suction temperature - low pressure saturation temperature
at all outdoor units or 6 minutes have elapsed since the start.
< Operation >
COMPRESSOR: Performed by all INV compressors operating up until now
INV speed varies depending on the operation state.
EEV Opening (Indoor/Outdoor unit): Controlled pulse (as normal operation mode).
FAN speed (Indoor/Outdoor unit)
Heating oil recovery operation
< Start condition >
Compressor accumulated operation time since the last heating oil recovery exceeds 8 hours
(first time : 1hour)
< End condition >
After 4 minutes have elapsed
< Operation >
COMPRESSOR: Performed by all INV compressors operating up until now
INV speed varies depending on the operation state.
EEV Opening (Indoor/Outdoor unit) : Controlled pulse (as normal operation mode)
FAN speed (Indoor/Outdoor unit)
Others
During the oil recovery operation,
and
The operation indicators (LED) of the indoor units flash slowly.
2-6-2 Pre-heat Operation
This pre-heat operation protects the start up failure by preventing the refrigerant from soaking into the oil in compressor.
2 pcs of belt heater installed on the compressor
The crankcase heaters are controlled by the outdoor temperature
< Control condition >
Crankcase heater ON: 30 minutes elapsed since installed compressors stopped
5
3
: Controlled fan speed (as normal operation mode).
: Controlled fan speed (as normal operation mode)
appears on the display of wired and central remote controller,
appears on the simple remote controller.
(However, ON when power turned on)
OFF: Installed compressors operation
35W (1 pcs)
70W (2 pcs)
02-11
5deg"