8
Evaporator / Condenser water pump
The controller can regulate an optional evaporator /
condenser water pump.
Inlet Guide Vane
The Inlet Guide vane (IGV) is used to adjust the refrigerant
vapor flow into compressor to change in the operating
conditions of the machine. To adjust the refrigerant ow, the
guide vane moves open or close to vary the cross-section of
the refrigerant path. The high degree of accuracy with which
the guide vane is positioned ensures that the flow of
refrigerant is precisely controlled.
Economizer Damper valve (used for NGC chiller or the
chiller which is equipped with electrical damper valve)
The economizer damper control positions the economizer
damper valve open or closed to maintain a minimum
refrigerant pressure difference between the evaporator and
economizer.
Damper vapor source solenoid valve (used for 19XRC)
Damper vapor sorce solenoid valve adjusts the pressure
difference between Economizer and Evaporator according
to pressure difference between damper cap and ow passage.
EC Valve
The envelope control function is used to articially load the
chiller and keep it running under low load conditions or to
prevent surge conditions. Since this also reduces the operating
efciency of the machine, this is a user selectable option.
VFD
The VFD allows compressor start-up and capacity control
by modifying the motor frequency. The aviator continually
monitors many compressor parameters in order to ensure its
protection. If a problem occurs, the frequency aviator triggers
an alarm and, if necessary, stops the compressor.
The components listed below are available at the user’s
terminal block on the IOB. Some of them can only be used
if the unit operates in the remote operating type (Remote
mode).
The following table summarizes the connections at the I/O
boards.
19XR6/7 I/O Mapping:
Entering Chilled
Water Temperature
AI1 IOB1
Leaving Chilled Water
Temperature
AI2 IOB1
Entering Condenser
Water Temp
AI3 IOB1
Leaving Condenser
Water Temp
AI4 IOB1
Evap. Refrigerant
Liquid Temperature
AI5 IOB1
Comp Discharge
Temperature
AI6 IOB1
Condenser Pressure AI7 IOB1
Evaporator Pressure AI8 IOB1
Economizer Pressure AI9 IOB1
FS VFD Load Current AI10 IOB1 For Freestanding VFD
option
Chiller Status
Output mA
AO1 IOB1 User option, 4~20mA
4mA=OFF 8mA=Tripout
12mA=Shutdown
20mA=Running
Oil EXV Output
(4-20ma)
AO2 IOB1 Factory option, 4~20mA
Evap Wate
Flow Switch
DI1 IOB1 User option, dry contact,
“Closed” indicates “FLOW”
Cond Water
Flow Switch
DI2 IOB1 User option, dry contact,
“Closed” indicates “FLOW”
Remote Contact Input DI3 IOB1 User option, dry contact,
“Closed” indicates Turn ON
the chiller
Remote Emergency
Stop Input
DI4 IOB1 User option, dry contact,
“Closed” indicates chiller
emergency stop
Stage 1 IGV Increase DO1 IOB1 Used for ON/OFF type
guide vane actuator
Stage 1 IGV
Decrease
DO2 IOB1 Used for ON/OFF type
guide vane actuator
Chiller Alarm Relay DO3 IOB1 User option, 24VAC output,
recommend with external
power supply
Chiller Alert Relay DO4 IOB1 User option, 24VAC output,
recommend with external
power supply
Motor Winding
Temperature 1
AI1 IOB2
Motor Winding
Temperature 2
AI2 IOB2
Motor Winding
Temperature 3
AI3 IOB2
Oil Supply
Temperature
AI4 IOB2 Factory option
Oil Sump
Temperature
AI5 IOB2
Oil Supply Pressure AI6 IOB2
Oil Sump Pressure AI7 IOB2
Auto Demand Limit
Input
AI8 IOB2 User option, 4~20mA
Refrigerant Leak
Sensor
AI9 IOB2 User option, 4~20mA
Displacement Switch AI10 IOB2
Guide Vane1 Output AO1 IOB2
Damper Valve
Feedback Fully Open
DI1 IOB2
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