17
MAINTENANCE
(F)LS (ES, IA, MV, PX), FCR
3-phase asynchronous TEFV brake motors
5025 en - 2013.03 / a
LEROY-SOMER
en
5 - TROUBLESHOOTING GUIDE
Incident
Possible cause
Action
Abnormal noise
Originating in motor or driven machine?
Uncouple the motor from the driven equipment and
test the motor on its own
Test the brake release system
Noisy motor
Mechanical cause:
if the noise persists after
swit ching off the electrical power supply
- vibration
- Check that the key conforms with the type of
balan cing
- damaged bearings
- Change the bearings
- mechanical friction: ventilation, brake disc, coupling
- Check
Electrical cause:
if the noise stops after switching
off the electrical power supply
- Check the power supply at the motor terminals
- normal voltage and 3 phases balanced
- Check terminal block connection and tightening of
the connectors
- abnormal voltage
- Check the power supply line
- phase imbalance
- Check the winding resistance and the supply
(vol tage) balancing
Motor heats up
abnormally
- faulty ventilation
- Monitor the environment
- Clean the fan cover and the cooling fins
- Check the fan is correctly mounted on the shaft
- faulty supply voltage
- Check
- terminal connection fault
- Check
- overload
- Check the current consumption against the current
shown on the motor nameplate
- partial short-circuit
- Check the electrical continuity of the windings
and/or the installation
- phase imbalance
- Check the windings resistance
Motor does not start
no load
- mechanical locking
- broken supply line
Release the brake, and with the motor switched off:
- check the shaft rotates freely by hand
- check fuses, electrical protection, starting device,
electrical continuity
on-load
- phase imbalance
When switched off:
- check the direction of rotation (phase order)
- check the resistance and the continuity of the
win dings
- check electrical protection
The brake does not release
Insufficient supply voltage:
Defective coil:
The maximum permissible voltage drop is 15 % of
the rated voltage
Change the coil
The brake releases but it is
very noisy:
Air gap irregular, or too large:
Foreign body in the air gap:
Dismantle if necessary and clean (see §4)
Clean the parts
The brake releases but
braking is insufficient
Insufficient pressure on springs:
Correct pressure on springs:
Adjust springs (see instructions §4) and
Check for wear on the linings
Check the surface condition of the ring and the brake
shield
Blow away any friction dust
