Sinclair SDV 6 Service Manual page 44

6 Control
6.1 Temperature Compensation Control
Because of the installation position of Indoor Unit and different layout, indoor temperature detected by Indoor Unit may
not consist with actual temperature. Indoor temperature could be compensated by controller (The parameter code is"N25"
"N26")
6.2 EEV Control
When the IDU is powered on again or the ODU is stopped, the system automatically enters initialization mode. After
initialization is completed, the system enters the normal start mode. The IDU EEV uses superheat degree control in cooling
mode and uses supercool degree control in heating mode. If the IDU receives a protection control or special control
command, this command is executed in priority.

Superheat Degree Control in Cooling Mode
During cooling (dry), the IDU calculates the difference between the heat exchanger gas pipe temperature (T2B) and the
heat exchanger liquid pipe temperature (T2A) detected by the temperature sensors and write this difference as the current
superheat degree (SH). By comparing the current superheat degree (SH) with the set superheat degree (SHS), the opening
adjustment trend of the EEV can be decided.

Supercool Degree Control in Heating Mode
During heating, the IDU calculates the difference between the High pressure equivalent saturation temperature (Tc) and
the heat exchanger liquid pipe temperature (T2A) detected by temperature sensors and write this difference as the current
supercool degree (SC). By comparing the current supercool degree (SC) with the set supercool degree (SCS), the opening
adjustment trend of the EEV can be determined.

EEV Operating in other Situations
The EEV decides its operating opening based on the IDU operating mode, IDU working mode, and ODU working mode. For
details, see the following table:
Cooling Mode
IDU Status
ODU Operating
Operating Superheat control
Standby
Off A PLS
Fault
Note:
1. PLS indicates the unit of pulses regarding the EEV opening.
2. The values of A,B,C and D are depend on IDUs' series.
 When SH > SHS, the EEV opening increases

When SH = SHS, the EEV opening unchanged
 When SH < SHS, the EEV opening decreases
SC＝max（T1+6,Tc_max-2）-T2A
 When SC > SCS, the EEV opening increases
 When SC = SCS, the EEV opening unchanged
 When SC < SCS, the EEV opening decreases
Heating Mode
ODU Stopped ODU Operating
Supercool control
B PLS
C PLS
SH＝T2B-T2A
ODU Stopped
D PLS
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