EN - 39
EN - 38
Oil Level Control Method
Oil Level Control and Oil Addition Assessment Criteria
When the connection piping is long, oil in the refrigeration unit tends to attach to the in inner surface of the piping,
resulting in insufficient oil in the compressor. When the piping length exceeds 50 m, add oil according to the table
below.
Connected pipe length
Additional oil quantity
(per refrigeration unit)
50 m or below
0.0 L
More than 50 m but 100 m or below
1.0 L
After adding the oil quantity shown above, check the oil level and adjust oil addition while operating the refrigeration
unit.
(1) Checking the change of oil level
Set the rotary switch (knob) on the control PCB to [OPERATION MODE] , and turn ON the DIP switch SW13-7 to
enter the oil level confirmation mode.
< Digital display example (Oil level) > (E.g.) Oil level upper limit indication
Upper limit
Mid level
Lower limit
[ Checking method ]
During continuous operation of the refrigeration unit, confirm whether the oil quantity is appropriate by checking
the oil level indicated by the digital display. (Exclude the initial start-up time)
•
Correct operation
The oil level generally stays between “Lower limit - Mid level - Upper limit”, and no Oil level anomaly (E391) is
occurred.
(E.g.) 1) Changing as . . . . . . Lower → Mid level → Upper → Mid level → Lower → Mid level.
2) Changing as . . . . . . Lower → Mid level → Upper → Mid level → Upper → Mid level.
Note
: The time of change varies according to the operation condition.
•
Abnormal motion (Insufficient oil supply)
1) The oil level does not recover from the lower limit position.
2) Lower limit condition continued for 10 minutes, and “Oil level anomaly (E391)” occurred. (Stop the
compressor)
(2) Check the degree of opening of the oil control electronic expansion valve (MOV1)
Set the rotary switch (knob) on the control PCB to [STANDARD SETTING] position and turn ON the DIP switch
SW13-7. Press ▲ and ▼ to indicate “1” in the digital display and display the opening of the oil control electronic
expansion valve.
< Digital display example >
By operating ▲▼ (up and
down switch), set to “1”.
Electronic expansion valve opening
Display range (30 to 480 steps)
(E.g.) Electronic expansion valve
opening 480 steps
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