Functions
Si-95
20
Functions Inverter K Series
1.7
Oil Return Operation
In order to collect refrigeration oil held up in connecting piping, the compressor’s operating time is counted,
and oil return operation is carried out for 8 minutes 30 seconds every 8 hours (2 hour after turning on the
power supply, and every 8 hours after that).
(When heating, the indoor unit’s electric heater is tuned off one minute prior to oil return operation in
preparation for oil return.)
Operation Contents
Step 1
→
Discharge oil return
k = kg/cm
2
Compressor
86Hz + OFF
EEV
2000pls
Outdoor Unit Fan
H + ON
Outdoor Unit Heat Exchanger
Condenser
4 Way Valve
OFF
Injection 1
Td Protection Control
Injection 2
OFF
Hot Gas
ON at Lp < 0.3k
4 Minutes Elapsed
Step 2
→
Suction oil return
Compressor
86Hz + OFF
EEV
2000pls
Outdoor Unit Fan
H + ON
Outdoor Unit Heat Exchanger
Condenser
4 Way Valve
OFF
Injection 1
Td Protection Control
Injection 2
Td Protection Control
Hot Gas
ON at Lp < 0.3k
4 Minutes Elapsed
∗
Td : Discharge Pipe Temperature
Step 3
→
BS solenoid valve changeover
Compressor
38Hz + OFF
EEV
2000pls
Outdoor Unit Fan
H + ON
Outdoor Unit Heat Exchanger
Condenser
4 Way Valve
OFF
Injection 1
Td Protection Control
Injection 2
OFF
Hot Gas
ON at Lp < 0.3k
30 Seconds Elapsed
Step 4
→
Refrigerant is discharged from accumulator
Compressor
76Hz + OFF
EEV
Limit of Opening
Outdoor Unit Fan
H + ON
Outdoor Unit Heat Exchanger
Evaporater
4 Way Valve
ON
Injection 1
Td Protection Control
Injection 2
OFF
Hot Gas
Low Pressure Protection Control
5 Minutes Elapsed
Hp > 14k
R5T > Te + 10ºC
* Te : Low Pressure Equivalent
Saturated Temperature
Normal Control
Preparation
for Oil Return
Upper Limit Frequency
Limited to 38Hz + ON
1 Minute
Elapses
(VF014)
SI-95.BOOK Page 20 Friday, March 31, 2000 10:59 AM