Compressor Configuration
8
Danfoss Turbocor Compressors Inc.
ECD-00007M Rev. 1
• Modbus Network: the compressor receives a
demand from an external computer, PLC, or
building management system using the Modbus
protocol on a RS-232 or RS-485 communication
link.
• Chiller Control: fully automatic; controls the chilled
water temperature using a temperature sensor
connected directly to the Chiller Interface module.
This mode can also be used to control evaporating
temperature which is derived from the suction
pressure measurement
NOTE:
If the compressor is linked to an external controller, changes
made to the compressor demand via the monitor program
can conflict with controller-issued commands. This
situation can lead to unexpected results. Before testing the
demand input, isolate the compressor from the controller.
4.
Click the Next button.
Steps 5 through 8 apply to the Chiller Control mode
only.
5.
Select the type of sensor that will control the chiller. If
selecting Entering or Leaving Chiller Air/Water
Temperature, connect an NTC temperature sensor (as
specified in the compressor Application manual) to
either the Entering- or Leaving Chilled Water
temperature input on the Chiller Interface module.
6.
Set the Chiller Control Set Point to the desired value.
7.
Set the Proportional and Integral Gain values to obtain
stable control (the Proportional and Integral Gain
values will vary depending on the application).
NOTE:
The Integral part of the internal chiller controller is
switched off until the compressor reaches a speed of 18,500
RPM. Stopping the compressor and restarting also resets the
Integral part to 0.
8.
Click in the Chiller Enable checkbox if you would like
to have the compressor start automatically. It is
advised, however, to open the interlock contact (located
on the Chiller Interface module) to prevent the
compressor from starting before the commissioning
sequence is complete.
4.1.1 Start-up Settings
(Refer to Figure 8)
1.
Enter the Temporary Suction Pressure Alarm %. The
limit is set up as a % of the current suction pressure
limit, e.g., if a suction pressure trip of 270 kPa was set
and the temporary suction pressure alarm was set to
50%, the temporary suction pressure trip limit would
be 135 kPa. This temporary alarm is only active while
the Suction Pressure Delay timer is counting down.
Figure 6 General Compressor Settings
Figure 7 Chiller Control Commissioning