ABB AV2123000 Positioner User Manual

SECTION 4 - CALIBRATION
INTRODUCTION
This section contains the following information:
• Calibration.
• Gain adjustment.
• Speed control.
• Troubleshooting calibration.
NOTES:
1. All procedures in this section assume direct acting operation.
2. The troubleshooting calibration procedure in this section is
not required for normal operation. The procedure is used only
when operating difficulties occur. The corrective action column of
Table 6-1 indicates when to use the troubleshooting calibration.
3. Calibration can also involve cam shaping to achieve the
required control characteristics. Refer to Appendix C for detailed
information about the cam.
CALIBRATION
Tools required:
3⁄
32
-inch Allen wrench.
Mechanical linkage is performed during installation (Section 3)
that normally consists of adjusting the connection between the
positioner and actuator so that the mechanical zero on the positioning
cam corresponds to the mechanical zero of the actuator.
The calibration procedure detailed here involves fine adjustments
to the zero and span such that the input signal will cause the
desired travel.
Calibration consists of applying an input signal pressure to the
positioner to set the zero and span. These adjustments are made
with the supply air applied to the positioner.
Type AV positioners have position transmitter options that are
available for feedback purposes. Refer to Appendix A for more
information about the position transmitter options.
Zero Adjustment
The positioner zero adjustment sets the tension on the range
spring and adjusts the input signal level that causes the actuator
to move off of the minimum travel stop. The zero percent radial
line of the cam should align with the center of the cam roller (Fig.
4-2).
INTRODUCTION
4 - 1