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Revision 8.6
SECTION 1 : GENERAL
7
SPECIAL FEATURES
FEATURE
ADVANTAGES
Excellent control
Load independent control
o
Excellent repeatable placing of end load
o
Safer working environment for personnel
Smooth steady control
o
Safe efficient load handling
o
Gearbox and couplings not subjected to excessive stress
o
Reduced current peaks
Slip-ring maintenance reduced
Motor life extended
Safe brake control
o
Torque proving before brake is opened (Hoist only)
o
Brake is used only as a parking brake and in emergency
conditions
o
No more continual replacing of brake parts.
Rotor feedback speed measurement
No tacho generator or pulse encoder required
o
No mechanical modifications needed on motor shaft
o
No additional installation costs, labour and equipment
o
No maintenance of a tacho required
o
No need for small control wires in cable loop system
o
Simplifies the control system
Reversing contactors
Reversing contactors are used to change torque direction on motor
o
Improved reliability as compared with static bridge system
Contactors are switched during zero current conditions
o
No maintenance on contact tips
o
Contactor life extended
Simplicity
Simple quick installation
Training easy to perform
Understood easily by maintenance staff
o
Faults on crane easy to find
Loss of production eliminated
o
Rapid acceptance by maintenance staff
Large range
Covers complete crane range
o
Control system the same for any size motor
o
Ideal for single motor use with emergency operation
requirement.
