9
Troubleshooting
39
Limitorque L120-85 Installation, Operation and Maintenance FCD LMENIM1202-03-A4 – 06/15
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WARNING:
Be aware of electrical and high-pressure hazards when troubleshooting or performing maintenance
on your L120-85 actuator.
Symptom
Possible Cause
Corrective Action
Actuator will not operate electrically
1. No power to actuator
1a. Verify electrical supply is phased correctly and present at actuator.
1b. Verify electrical power leads are connected in accordance with the
applicable wiring diagram.
1c. Inspect for tripped circuit breaker, overload, open disconnect switch, or
blown fuse.
2. Loose or incorrect wiring
2. Check wiring for proper connections in accordance with the applicable
wiring diagram. Also check for loose connections.
3. Limit Switches not set or
incorrectly set
3. Check Limit Switch development for agreement with the applicable
wiring diagram. If not set properly, follow instructions for “Setting Limit
Switches”.
4. Foreign material on switch
contacts preventing good
electrical contact
4. Check continuity of switches with an ohmmeter.
Motor runs, but no output from
actuator
1. Actuator not coupled properly to
output
1. Inspect Torque Drive Nut and Valve Shaft to verify key is in place and
properly staked.
2. Torque Drive Nut disengaged
from Drive Sleeve
2. Verify Torque Drive Nut is properly installed in accordance with step 1 of
the Installation Overview.
3. Worm gear worn out
3. Remove Worm Shaft Assembly (following Disassembly Instructions).
Inspect worm gear for unusual wear. If excessive wear has occurred,
replace the Worm Shaft Assembly.
4. Damaged gearing
4. Disassemble actuator following the Disassembly Instructions and
inspect gearing for rough or damaged spots. Replace as required. Most
frequently, damaged spots are seen in motor gear set.
Actuator operation is noisy
1. Inadequate lubrication (poor
quality or not enough)
1. nspect quality and quantity of lubrication in accordance with the
Lubrication section. Add or replace lubricant as required.
2. Worn or damaged bearings
2. Disassemble actuator and replace worn bearings, seals and lubricant.