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Operation Manual
D
–EOMWC00A07-16_02EN
Start
Start the connection to DoS
Comm State
-
Connection to DoS is off
IPErr
Connection to DoS cannot be established
Connected
Connection to DoS is established and working
Remote Update
Enable
Enable the Remote update option
Disable
Disable the Remote update option
8
CIRCUIT FUNCTIONS
8.1
Calculations
8.1.1
Refrigerant Saturated Temperature
Refrigerant saturated temperature is calculated from the pressure sensor readings for each circuit. A function provides the
converted value of temperature to match values published data for R134a, R1234ze and R513a
8.1.2
Evaporator Approach
The evaporator approach is calculated for each circuit. The equation is as follows:
Evaporator Approach = LWT
– Evaporator Saturated Temperature
8.1.3
Suction Superheat
Suction superheat is calculated for each circuit using the following equation:
Suction superheat = Suction Temperature
– Evaporator Saturated Temperature
8.1.4
Discharge Superheat
Discharge superheat is calculated for each circuit using the following equation:
Discharge superheat = Discharge Temperature
– Condenser Saturated Temperature
8.1.5
Oil Differential Pressure
Oil Differential Pressure is calculated for each circuit with this equation:
Oil Differential Pressure = Condenser Pressure - Oil Pressure
8.1.6
Maximum Saturated Condenser Temperature
The maximum saturated condenser temperature calculation is modeled after the compressor operational envelope. Its
value is 68.3°C basically but it can change when saturated evaporator temperature decreases below 0°C.
8.1.7
High Saturated Condenser
– Hold Value
High Cond Hold Value = Max Saturated Condenser Value
– 2.78
C
8.1.8
High Saturated Condenser
– Unload Value
High Cond Unload Value = Max Saturated Condenser Value
– 1.67
C
8.1.9
Condenser Saturated Temperature Target
The saturated condenser temperature target is calculated to maintain the proper pressure ratio, to keep the compressor
lubricated and to have the maximum circuit performances.
The calculated target value is limited to a range defined by the Condenser Saturated Temperature Target min and max set
points. These set points simply cut off the value to a working range, and this range can be limited to a single value if the
two set points are set to the same value.
