Section 6 - Troubleshooting; Introduction; Positioner Errors - ABB AV1 Operating Instructions Manual

INTRODUCTION

WARNING
Error Probably Cause
Oscillation of Drive arm not
actuator securely attached to
actuator.
Pneumatic signal
leak.
Pilot valve sticking.
Gain too high.
Actuator at one end Air lines in wrong
of stroke and does ports.
not respond to input
Incorrect cam
change
installed for applica-
tion.
Pneumatic signal
leak.
Mechanical calibra-
tion shift.
I/P converter not
functioning.

SECTION 6 - TROUBLESHOOTING

This section provides information about the Type AV positioner
when operating difficulties are encountered. A table listing errors,
probably causes and corrective actions allows the operator to
troubleshoot a problem pertaining to the positioner.
If a problem occurs and is traced to the positioner, check the sup-
ply pressure, input and output connections, and mechanical
adjustments before removing it from service.
Disconnect the supply signal source or remove the equip-
ment from the process before servicing. Failure to do so
can cause unexpected movement posing a risk of bodily
injury.
Table 6-1. Positioner Errors
Tighten or correct linkage as necessary.
Check for leaks in connectors or fittings.
Remove pilot valve and clean or replace. Refer to
Assembly in
Change gain hinge spring to greater thickness. Refer to
Hinge Spring
Check air line connections (Figs. 3-10, 3-11, 3-12,
3-14).
Determine application (reverse or direct acting) and check for
correct cam (Figs. 3-10, 3-11, 3-12,
AV1: Check input signal connection for leaks at I port.
AV2: Check signal at I port. If pressure is between 20.7 and
103.4 kPa (3.0 and 15.0 psig) and responds to input signal
change then problem exists elsewhere.
If pressure is not between 20.7 and 103.4 kPa (3.0 and
15.0 psig) or does not respond to input change, check for
leaks inside positioner and check I/P converter calibration
(refer to TROUBLESHOOTING CALIBRATION ADJUST-
MENTS in Section
Make sure the linkage between positioner and actuator is tight
and has no backlash.
Check I/P converter calibration (refer to
ING CALIBRATION ADJUSTMENTS
Corrective Action
Section 8.
in Section 8.
3-13
4).
TROUBLESHOOT-
in Section
Pilot Valve
Gain
3-13 and
and 3-14).
4).
INTRODUCTION
6 - 1