Emerson 20/20 service manual Analog Outputs, Digital & Analog I/O Boards Layout

Section 3 • Hardware Architecture

Volume Position:

•Reads the 0-5 volt signal back from the slide volume motor actuator to indicate current volume position.

Suction Temperature:

•Default signal is RTD. Suction temperature calibra- tion is set in the calibration screen.

Discharge Temperature:

•Default signal is RTD. Discharge temperature calibra- tion is set in the calibration screen.

Oil Separator Temperature:

•Default signal is RTD. Oil separator temperature cali- bration is set in the calibration screen.

Oil Manifold Temperature:

•Default signal is RTD. Oil manifold temperature cali- bration is set in the calibration screen.

Process Temperature:

•Default signal is 4-20mA. Process temperature cali- bration and range are set in the calibration screen.

Chiller Inlet Temperature:

•Default signal is 4-20mA. Measures separator level. Chiller Inlet Temperature calibration and range are set in the calibration screen.

Condenser Pressure:

•Default signal is 4-20mA. Condenser pressure trans- ducer range and calibration is set in the calibration screen.

Remote Caphold:

•Default signal is 4-20mA. Active in “Direct I/O” mode. Adjusts the capacity of the compressor from 0-100%, proportional to the 4-20mA signal.

Auxiliary #1 - #16:

•Flexible analog inputs that can be configured to con- trol, alarm or trip.

Analog Outputs:

Refer to Table 2-3. Analog Outputs.

Compressor VFD:

•4-20mA output to control compressor motor speed with a Variable Frequency Drive (VFD).

Condenser VFD:

•4-20mA output to control one condenser fan which is interleaved between the remaining condenser steps for smoother control.

% Slide Valve Position:

•4-20mA signal that transmits the slide valve position for remote monitoring.

Motorized Valve (V+):

•For a cool compression compressor, this 4-20mA signal controls a motorized valve to regulate the liq- uid refrigerant level in the oil separator. For a liquid injection application on a standard single screw, this 4-20mA signal controls a motorized valve to regulate the liquid refrigerant injected into the compressor for oil cooling purposes.

Digital & Analog I/O Boards Layout

It is important to install the boards in the proper layout. For the correct digital and analog input/output (I/O) board layout, see Figure 3-2. Digital I/O Board Layout.

Dipswitches

•Each board has a dipswitch which sets its communi- cations address so that it can communicate with the CPU board. The dipswitch settings must be correct or the I/O will not function.

Jumpers

•Jumpers are required on the analog boards to con- figure them for the type of sensors used. The jumper table for the analog board shows the optional jump- er configurations for sensors other than the default Vilter standard. If a different sensor is to be used, the jumpers on the analog board need to be changed. In addition, the configuration for this sensor must be changed in the Instrument Calibration screen. The following illustrations show the Vilter default con- figurations for the Vission 20/20.

3 – 6 Vission 20/20 • Operation and Service Manual •Vilter/Emerson • 35391SC 1.8.5153