Troubleshooting Calibration Adjustments; Servo Assembly Adjustments (Type Av3 Positioner); Speed Adjustment Screw Locations - ABB AV3 Instruction Manual

TROUBLESHOOTING CALIBRATION ADJUSTMENTS

Servo Assembly Adjustments (Type AV3 Positioner)

Instruments Required:
WARNING
TO P A D JU S TM EN T S C R E W
AL LE N W R E N C H
A C C E S S
Figure 4-7. Speed Adjustment Screw Locations
The servo assemblies of the Type AV3/4 positioners come from
the factory completely calibrated. Use the following procedures
only when operating difficulties occur. The corrective action
column of Table 6-1 will prompt you to use the troubleshooting cal-
ibration.
The purpose of this procedure is to adjust the servo so that the
four to 20-milliamp input signal will produce a 20.7 to 103-kilopas-
cals (three to 15 pounds per square inch gage) signal. Use the fol-
lowing procedure to adjust the servo assembly.
Digital voltmeter
0 to 30 psig instrument gage
Small screwdriver
Current source
Type AV positioners are suitable for a maximum supply
pressure of 1034 kPa (150 psig). Do not exceed maximum
recommended final control element operating pressure.
1. If the positioner is mounted on an actuator and it is not desir-
able to have the actuator move during calibration, remove the air
lines from 01 and 02 ports. Plug the ports. If bench calibrating,
plug 01 and 02 ports to prevent excess air flow during calibration
(Fig. 3-7).
TROUBLESHOOTING CALIBRATION ADJUSTMENTS
CALIBRATION
S IG N A L
D IA P H R A G M
H IN G E S PR IN G
LO W E R A D JU S T M E N T
SC R EW
R A N GE S P R IN G
T 00 77 8 A
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