Special Control - Sinclair SDV5 Series Service Manual

7 Special Control

7.1 Oil Return Operation
In order to prevent compressors from running out of oil, the oil return operation is conducted to recover oil that has
flowed out of the compressor(s) and into the piping system. This operation is performed for all units including units that
are in standby.
Timing of oil return operation:
 When the initial cumulative operating time reaches every 8 hours.
Tables 3-7.1 and 3-7.2 show component control during oil return operation in cooling mode.
Table 3-7.1: Outdoor unit component control during oil return operation in cooling mode
Component
Inverter compressor
DC fan motor
Electronic expansion valve
Four-way valve
Tables 3-7.3 and 3-7.4 show component control during oil return operation in heating mode.
Table 3-7.3: Outdoor unit component control during oil return operation in heating mode
Component
Inverter compressor
DC fan motor
Electronic expansion valve
Four-way valve
Table 3-7.4: Indoor unit component control during oil return operation in heating mode
Electronic expansion valve
Note：Prevent cold wind：It's only valid in heating operation, and this control is priority to other controls (including heating oil return and
defrost), Which determine the conversion between setting fan speed with low fan speed and turn off the fan according to the evaporator coil
temperature T2.
24
Wiring diagram
label
COMP
FAN
EEV1
ST1
Table 3-7.2: Indoor unit component control during oil return operation in cooling mode
Component
Fan
Electronic expansion valve
Component Unit state
Thermo on
Fan Standby
Thermo off
Thermo on
Standby
Thermo off
8~16kW
Fixed frequency
●
● Normal control as cooling operation
Position 300 (steps)
●
Off
●
Unit state Control functions and states
Thermo on Remote controller setting
Standby Remote controller setting
Thermo off Off
Thermo on Normal control
Standby 300 (steps)
Thermo off 300 (steps)
Wiring diagram label 8~16kW
COMP
FAN
EEV1
ST1
Control functions and states
Operate on setting fan speed (Prevent cold wind priority)
Operate on setting fan speed (Prevent cold wind priority)
Off
Normal control
480 (steps)
480 (steps)
Control functions and states
Control functions and states
Fixed frequency
●
Fan speed controlled according to
● heat exchanger temperature (T3) and
outdoor ambient temperature (T4)
● Position 300 (steps)
● Off