HORA MC250/24 User Manual

10 Troubleshooting
Linear actuators MC250 • MC253 • MC500 • MC503
32 Version 2.1 - March 2011 Operating Manual
10.2 Operating faults checklist
Fault Cause/reason Remedy
1. Linear actuator does not
work.
Handwheel (36) is in manual mode position  Switch handwheel to automatic mode
position.
Mains power failure  Establish cause and eliminate.
Fuse defective. (in the electrical cabinet)  Establish cause and eliminate, change
fuse.
Linear actuator incorrectly connected  Rectify connection in accordance with
circuit diagram (on the cover).
Short circuit due to humidity  Establish cause, dry the linear actuator,
change hood seal and screw
connections if necessary ad/or fit
protective hood.
Short circuit due to incorrect connection  Rectify connection
Motor has coil damage (burnt out)
• e.g. due to too high voltage
• Electronic system defective
 Establish cause, measure current data
Compare with rating plate and table,
Remove linear actuator and return to
manufacturer for repair.
2. Linear actuator runs in an
unstable manner, i.e.
switches between clockwise
and counter-clockwise
rotation.
Voltage drop due to too long connecting
cables and/or too small cross-section.
 Measure linear actuator current data,
recalculate and change connecting
cables if necessary.
Mains power fluctuations greater than
permissible tolerance
 2.5 Technical data on page 10
 Improve mains power ratios
3. Linear actuator cuts out
from time to time or
initialises frequently.
Supply cable has loose contact  Check and tighten connections (terminal
strips)
4. Linear actuator does not
move to the limit positions.
Valve does not close/open.
Valve jams  Ensure smooth running valve
Too high system pressure  Correct system pressure
5. Linear actuator does not
move or does not move
correctly to the position
specified by input signal Y.
Input signal Y faulty:
• Error signals
• Signal fluctuations
 Check input signal Y on linear actuator,
eliminate cause of fault
Motherboard faulty  Change motherboard, remove linear
actuator and return to manufacturer for
repair if necessary.
6. Green LED flashes in long /
long rhythm
Lock detection has responded  Press INIT and observe actuator during
initialisation.
 Check valve for smooth running over
entire lift range.
7. Greed LED flashes in short /
long rhythm
Open circuit detected  Measure reference value voltage or
current on linear actuator.
8. Green LED flashes in long /
short rhythm
Relay contact adherence 
Check control
9. Red LED flashes regularly Actuator overheats  Motor has switched off automatically.
Automatic start-up after cooling down
Table 9 Operating faults checklist

HORA MC250/24 Specifications

General

Brand	HORA
Model	MC250/24
Category	Controller
Language	English