Calibrating The Four To 20 Ma Position Transmitter - ABB AV3 Instruction Manual

POSITION TRANSMITTERS

Calibrating the Four to 20 mA Position Transmitter

CALIBRATION
A - 6
d. Tighten the set screw on the small gear hub.
NOTE: If the mesh between the large and small gears is not tight,
adjust the position of the potentiometer mounting bracket (Fig. A-3)
so that backlash is eliminated.
e. Remove the ohmmeter from TB1-1 and TB1-2. Install the
cam, screw, flag, nut, and washer (Fig. A-3).
3. Connect the field wiring to the terminal block. Connect a DC volt-
meter between TB1-1 (-) and TB1-2 (+).
4. Move the actuator to the 80% position. Adjust the resistor in
series with the 24 VDC supply until the voltmeter reads 5 VDC.
5. Move the actuator to the 0% position to verify that the voltmeter
reads less than 5 VDC.
6. Move the actuator to the 100% position to verify that the voltme-
ter reads greater than 5 VDC.
7. Potentiometric calibration complete.
Labels located inside the positioner cover show the location of jump-
ers, test points, calibration pots, and field connection terminals for the
position transmitter (Fig.
1. Remove the FOR/REV jumpers, and place the CAL/OPER jump-
ers in the calibrate (CAL) position (Fig. A-4).
F O R W A R D
R E V ER S E
Figure A-4. Location of Calibration Features
for 4 to 20 mA Position Transmitter
2. Move the actuator to the 50% output position.
A-1 and A-4).
T P 2(+)
C AL IB R AT E Z ER O SPA N
O P E R ATE
T P 1(–)
T 00 78 9 A