Oil Return Operation - Daikin CMSQ200A7W1B Service Manual

Special Control
3.2

Oil Return Operation

In order to prevent the compressor from running out of oil, the oil return operation is conducted to recover oil flown out
from the compressor to the system side.
3.2.1 Oil Return Operation in Cooling Operation
[Start conditions]
Referring to the set conditions for the following items, start the oil return operation in cooling.
• Cumulative oil feed rate
• Timer setting (Make this setting so as to start the oil return operation when the initial cumulative operating time
reaches two hours after power supply is turned ON and then every eight hours.)
Furthermore, the cumulative oil feed rate is computed from Tc, Te, and compressor loads.
Outdoor unit actuator
Compressor
Outdoor unit fan
Four way valve
Main motorized valve (EV1)
Subcooling motorized valve (EV2)
Hot gas bypass valve (SVP)
Accumulator oil return valve (SVO)
Ending conditions
Fan
Electronic expansion valve
40
Oil return preparation
operation
Take the current step as the
upper limit.
Fan control (Normal cooling) Fan control (Normal cooling) Fan control (Normal cooling)
OFF
480 pls
SH control
OFF
ON
20 sec.
Indoor unit actuator
Thermostat ON unit
Stopping unit
Thermostat OFF unit
Thermostat ON unit
Stopping unit
Thermostat OFF unit
Oil return operation
CMSQ200A7: 52 Hz
(→ Low pressure constant
control)
CMSQ250A7:
52 Hz
(→ Low pressure
constant control)
↓
Maintain number of
compressors in oil
return preparation
operation ON
OFF
480 pls
0 pls
OFF
ON
• 3 min.
or
• Ts - Te<5°C
Cooling oil return operation
Remote controller setting
Remote controller setting
Normal opening
Normal opening with forced thermostat ON
SiBE28-805
Post-oil-return operation
"
Same as the oil return
"
operation mode.
OFF
480 pls
0 pls
OFF
ON
• 3 min.
• Pe<0.6MPa
or
• HTdi>110°C
OFF
224 pls
Function