Section 6: Troubleshooting; Fault Insertion - Emerson Bettis CBA*30-SR series Service Instructions Manual

Service Instructions
137463E Rev. D

Section 6: Troubleshooting

6�1

Fault Insertion

In the unlikely event of a fault developing, the following Fault Location Table is provided to
assist the service engineer to perform troubleshooting. This table is designed to cover as wide
a range of Emerson Bettis actuators as possible. Reference to equipment not supplied should
be ignored.
Table 3�
SYMPTOM
Erratic movement
Short stroke
Apparent lack
of torque
Troubleshooting
Fault Location Table
POTENTIAL CAUSES
Irregular supply of operating
medium
Inadequate lubrication
Worn parts
Defective valve
Incorrectly set stops
(valve and /or actuator)
Hardened grease
Debris left in the cylinder or
housing during maintenance
Defective valve
Inadequate supply pressure
Incorrect speed control settings
Exhaust port blocked
Pipe work blocked, crushed
or leaking
Defective controls
Defective piston seal
Defective rod seal
Defective housing seal
High valve torque or valve seized Consult the valve OEM documentation
Section 6: Troubleshooting
REMEDY
Check operating medium for consistent
supply pressure and correct as necessary
Dismantle, relubricate and reassemble
Dismantle. Visually inspect for significant
wear. Actuator replacement may be required
Consult the valve OEM's documentation
Check the position of the travel stops and
readjust as necessary
Dismantle, remove any hard grease,
relubricate and reassemble
Disassemble cylinder assembly to remove
debris. Reassemble cylinder assemble as
necessary
Consult the valve manufacturer's
documentation
Ensure supply pressure is above the minimum
operating pressure of the actuator and that
output torque produced at supply pressure
exceeds valve torque demand
Adjust speed controls to increase flow
Remove and clean the exhaust port silencers
and replace
Examine the pipe work for blockages,
crushed pipe or leakage. Clear or replace
as necessary
Examine the controls, refurbish or renew as
necessary. Refer to component
manufacturer's documentation
Dismantle the cylinder assembly, remove
the defective piston seal. Fit new seal and
reassemble
Dismantle the cylinder assembly, remove the
defective rod seal. Fit new seal
and reassemble
Dismantle the housing assembly, remove the
defective seal. Fit new seal and reassemble
August 2015
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