Analog Inputs; Motor Current; 4-20Ma Scale - Emerson VILTER MicroVission Operation And Service Manual

Section 8 • Instruments Calibration

Analog Inputs

Page 3 of Instrument Calibration Screen is dedicated to
instruments used for Motor Current and Process Control.

Motor Current

The MicroVission measures the motor current value us-
ing the 4-20 mA signal transmitted from the external
device.
The calibration process for Motor Current is slightly dif-
ferent from all other calibration procedures. The mo-
tor current must be calibrated while the compressor
is running at close to full amps as much as possible. In
addition, the operator will need a value into the "Enter
Desired Value" entry box that is equal to the measured
value in amps by a calibrating measurement device.
After entering the measured value, the displayed motor
current in "Calibrated Value" field may still be off slightly.
In this case re-enter the desired value and the displayed
value should get progressively closer.
Figure 8-9. Instrument Calibration Screen Page 3 – Analog Inputs (Motor Current)
8 – 6

4-20mA Scale

• 4mA: Not editable by the operator. Defines the
minimum value in Amps represented by 4mA input..
• 20mA: Defines the maximum value in Amps that
represented by 20mA input.
• Enter Desired Value: The operator enters the cor-
rect current value. Each entry will re-calculate the
point slope calculations of the current calibration.
• Total Error: Not editable by the operator. Displays
the total error offset of the value from the "Enter
Desired Value" setpoint.
MicroVission Controller • Operation and Service Manual • Emerson • 35391MV 1.3