Fisher D500243X012 - Manual (Page 12)

Instruction Manual
D500243X012
1035/El-O-Matic Actuator
August 2012
12
Figure 5 . Code A Assemblies
A B A B
DOUBLE ACTING SPRING RETURN
A7047
Troubleshooting
If the actuator does not function, make the following checks:
1. Check for worn teeth on piston racks, if the actuator exhibits excessive amounts of backlash. If worn, replace
piston/gear rack assembly.
2. Check supply pressure to ensure the air supply is reaching the actuator. Place a gauge in the line at the inlet of the
actuator. Monitor the gauge for unexpected pressure drops when operating pressure is applied to the actuator.
3. Check piston seal leakage. For spring return actuators, piston seal leakage will show at port B when port A is
pressurized. For double acting actuators, piston seal leakage will show at port B when port A is pressurized, or vice
versa.
4. Check actuator movement. Remove the actuator from the valve. Apply reduced air pressure [0.7 to 1.0 bar (10 to
15 psi) for double acting, or 1.4 to 2.0 bar (20 to 30 psi) for spring return] to see if the actuator will cycle under a
no-load condition.
D If the actuator cycles under a no-load condition, please refer to the valve instruction manual for valve
troubleshooting or contact your Emerson Process Management sales office.
D If the spring set number is 5 or 6, it may not cycle with the reduced air pressure amounts listed above and may
require retesting with up to 5.5 bar (80 psi) to stroke a full 90 degrees.
D If the actuator does not cycle, disassemble the actuator using the Actuator Disassembly procedures. Inspect and
replace parts as necessary.
If the actuator and valve are moving freely, reassemble the valve/actuator assembly and re-test. If unit still fails to
operate, consult your Emerson Process Management sales office for assistance.