Emerson 20/20 service manual Refer to -2. Analog Inputs Motor Current

Section 3 • Hardware Architecture

High Level Shutdown Input:

•This input must be energized in order for the com- pressor to operate. If de-energized, the compressor will shut down and issue a high level trip.

Oil Level Float Switch #1 Input:

•Used for Cool Compression. Oil Level Float Switch #2 Input:

•Used for Cool Compression. Remote Select #1/#2 Input:

•This input enables or disables remote I/O control. Energizing this input enables the Remote Capacity Increase and Remote Capacity Decrease inputs.

Remote Start/Stop Input:

•If the compressor is enabled for remote I/O control, this input is enabled. Energizing this input will issue a start for the compressor as long as it is available to run. De-energizing this input stops the compressor.

Remote Capacity Increase Input:

NOTE

The scan interval on the remote increase and decrease inputs is approximately ONE SECOND. Please take that into account when developing a control scheme using the remote increase and remote decrease inputs for compressor control.

•If the compressor is enabled for remote I/O control, this input is enabled. Operational only when the com- pressor is running. Energizing this input will increase the slide valve position.

•The slide valve will continuously increase as long as this input is energized. The slide valve will not in- crease when this input is de-energized.

Remote Capacity Decrease Input:

•Operational only when the compressor is running. This input is enabled if the compressor is enabled for remote I/O control. Energizing this input will de- crease the slide valve position. The slide valve will continuously decrease as long as this input is ener- gized. The slide valve will not decrease when this in- put is de-energized.

Condenser Step #1 Output:

•This output is enabled when condenser control op- tion is selected. A condenser fan or pump will be turned on or off by this output.

Condenser Step #2 Output:

•This output is enabled when condenser control op- tion is selected. A condenser fan or pump will be turned on or off by this output.

Condenser Step #3 Output:

•This output is enabled when condenser control op- tion is selected. A condenser fan or pump will be turned on or off by this output.

Condenser Step #4 Output:

•This output is enabled when condenser control op- tion is selected. A condenser fan or pump will be turned on or off by this output.

Auxiliary Inputs #1 - #8:

•Optional inputs that can be configured as an alarm or trip. Typically connected to external switched devices.

Auxiliary Outputs #1 - #4:

•Optional inputs that can be configured as an alarm or trip. Typically connected to external switched devices.

Analog Inputs

Refer to Table 2-2. Analog Inputs.

Motor Current:

•Default is a 0-5 Amp current transformer (CT). Current transformer ratio is set in the calibration screen.

Suction Pressure:

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

Discharge Pressure

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

Oil Filter Inlet Pressure:

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

Oil Manifold Pressure:

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

Economizer Pressure:

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

Slide Valve Position:

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

3 – 4 Vission 20/20 • Operation and Service Manual •Vilter/Emerson • 35391SC 1.8.5153