Troubleshooting - DEMAG ZBA Assembly Instructions Manual

10 Troubleshooting

Item Problem
1 Motor does not start.
2 Motor does not start or starts
slowly.
3 Motor will not start in star connec-
tion, only starts in delta connection.
4 Incorrect direction of rotation.
5 Motor hums and has high power
consumption.
6 Fuses trip or motor protection trips
immediately.
7 Extreme loss of speed under load.
8 Excessive motor temperature rise
(measure temperature).
9 Excessive noise.
10 Brake does not release.
11 Motor does not brake.
Possible cause
Fuse has tripped.
Power supply line interrupted.
Motor protection has tripped.
Control defective.
Brake does not release.
Motor for delta connection is connected in star.
Extreme voltage or frequency deviation from setpoint
value.
Insuffi cient torque in star connection.
Contact fault in star-delta starter.
Motor incorrectly connected.
Winding defective.
Short-circuit in the supply line.
Short-circuit in the motor.
Power supply leads incorrectly connected.
Motor earth fault.
Overload.
Voltage drop.
Overload.
Insuffi cient cooling.
External fan not running.
Ambient temperature too high
Delta connection instead of star connection as specifi ed.
Temporary two-phase operation.
Fuse tripped.
Supply voltage diff ers from the rated motor voltage by
more than 10%. Higher voltages are particularly unfa-
vourable for low-speed motors as their no-load current is
close to the rated current even at normal voltage.
Duty type (S1 - S10, EN 60034-1) exceeded, e.g. starting
frequency is too high.
Anti-friction bearing distorted, dirty or damaged.
Rotating parts vibrating.
Foreign bodies in cooling air circuit.
Incorrect voltage applied to brake control module
Brake control module failure.
Maximum permissible air gap exceeded because the
brake lining is worn out.
Voltage drop in the power supply line > 10%.
Brake coil short-circuit with the winding or housing.
Brake lining worn out.
Manual brake release device incorrectly adjusted.
Manual brake release device locked.
Incorrect brake torque.
Solution
Replace fuse.
Check connections.
Check motor protection for correct setting.
Check motor connection.
See item 10 "Brake does not release"
Correct motor connection.
Improve quality of power supply; check power
supply line cross-section.
If the delta starting torque is not too high, start up
direct in star connection; otherwise use a larger
motor or special design (contact manufacturer).
Eliminate fault.
Swap two supply lines.
Motor must be sent to specialist workshop for
repair.
Eliminate short-circuit.
Motor must be sent to specialist workshop for
repair.
Correct motor connection.
Motor must be sent to specialist workshop for
repair.
Measure output, use larger motor or reduce load,
if necessary.
Use larger power supply line cross-section.
Measure output, use larger motor or reduce load,
if necessary.
Improve cooling air circulation or clear air circula-
tion channels; install external fan, if necessary.
Check connection, correct, if necessary.
Reduce power; use larger motor, if necessary.
Correct motor connection.
Intermittent electric contact in the power supply
line.
Replace fuse.
Match motor to power supply voltage.
Adapt operating conditions to corresponding motor
duty type.
Re-align motor, inspect anti-friction bearings,
replace if necessary.
Correct any imbalance.
Clean cooling air paths.
Apply correct voltage (see rating plate).
Replace brake control module, check brake coil
(resistance), check switchgear components.
Adjust the brake (replace the complete brake lining
carrier if the lining is worn out).
Ensure correct supply voltage is applied.
Replace complete brake with control unit (special-
ist workshop), check switchgear components.
Replace the complete brake lining carrier.
Set adjusting nuts to correct setting.
Release locking mechanism, remove lever.
Change brake torque.
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