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Revision 8.6
SECTION 6 : OPERATION OF CONTROL PANEL
91
6.8.10 Motor Stall
Motor is not turning when a running command has been given for a period greater than approximately
10 seconds.
Possible causes
Mechanical components have seized making it impossible for the motor to turn.
Mechanical brake does not release.
Excessive load on the hook, but not heavy enough to force a loss of torque when
hoisting.
Travel running against the end stops.
Travel wheels stuck into worn travel rails.
Travel wheels stuck in between rail joints.
6.8.11
Input Phases
Mains supply faulty:
Loss of a phase.
Wrong phase rotation.
Input phases have a RMS value < 70% of rated supply.
Possible causes
Supply to the drive has a single phase due to loose connections, down shop conductor
system faulty, single phase on supply switchgear such as main circuit breaker, crane main
contactor and crane main isolator.
The phase rotation is incorrect or has been made incorrect during maintenance routine work
on supply rails
Mains supply dropped below 70% of its rated value.
If all the above is in order replace the Phase Shifter card with a spare one or one from
another unit. If this proves to solve the problem the card input phases circuit is faulty.
6.8.12
Plugging Timeout
During retardation from full speed lowering a time out facility is included to ensure that, in the event
that the motor is unable to retard to neutral or to hoisting depending on the position of the master
controller, within the time set by the respective parameter, the brakes will close immediately after the
set time has expired and this fault will be displayed and stored in the fault history.
Possible causes
Sudden loss of torque during lowering plugging caused by a drop in supply voltage, rotor
resistance open circuit on one or more phases.
Excessive load being handled by the crane.
Unrealistic parameter time setting
