Upper/Lower Limit Switch - KITO ER2 Serie Manuel Du Propriétaire

Chapter 3 Troubleshooting
Troubleshooting (continued)

Upper/Lower Limit Switch

Symptom
Electric chain hoist
does not operate.
(Electromagnetic
Contactor or VFD
does not operate.)
Electric chain hoist
does not stop at the
upper/lower limit.
3
106
Cause
Contact point fusing Actuate the limit switch manually to
check the conduction of the contact
points.
Replace the limit switch as a whole when
no conduction.
Breakage Check the wiring. Repair or replace the
limit switch as a whole if the limit switch
has no conduction.
Moving part rusted Check the moving part of the limit switch
shut (defective such as actuator lever is not stiff. If it is
return action of the stiff, remove the rust or replace the stiff
moving part) part.
Contact point Actuate the limit switch manually to
welding check the conduction of the contact
points.
Replace the limit switch as a whole when
it does not turn off.
Moving part rusted Check the moving part of the limit switch
shut such as actuator lever is not stiff. If it is
stiff, remove the rust or replace the stiff
part.
Wrong wiring Check the wiring in accordance with
the wiring diagram. Perform the wiring
correctly.
If the wiring of the limit switch is correct,
the cause is in the negative phase
connection. Change two wires of the
power line.
Remedy
Habitual use of the limit
switch
Vibration, impact
Leaving the electric
chain hoist for a long
time at the upper/lower
limit.
Habitual use of the limit
switch
No use for a long time,
use in an environment
with rich moisture
Wrong wiring
Main factor Countermeasure
Do not use the limit switch
habitually.
Use the electric chain hoist
avoiding the impact.
Do not leave the electric
chain hoist at the upper/
lower limit.
Do not use the limit switch
habitually.
Check the electric chain
hoist regularly.
Correct the wiring in
accordance with the wiring
diagram.