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Revision 8.6
SECTION 5 : COMMISSIONING
75
5.4. HOIST OPERATION
The following paragraphs detail the operational procedures during hoisting operations;
5.4.1.
Hoisting
As soon as one of the four hoisting speeds on the master controller is selected, the THYROMAT will
activate the hoist contactors which will supply voltage to the motor, a short time delay is provided
before the brake is released. The motor will accelerate at a rate determined by the acceleration
profile. Selecting one of the three slow speeds will regulate the motor at the selected speed.
Selecting full speed will accelerate the motor smoothly until full speed is reached. Accelerating rotor
contactors will operate at specific speeds.
Bringing the master controller back from full speed to one of the slower speeds or to the zero position
will cause the drive torque to be removed from the motor until such time that the selected speed is
achieved. If the load is light and the deceleration ramp error sufficiently large the motor will be
slowed down by plugging, if the Hoist plugging parameter is set to True, otherwise the brake will
close immediately as the joystick returns to Neutral.
5.4.2.
Lowering With an Overhauling Load
As soon as one of the three lowering slow speeds on the master controller is selected, the
THYROMAT will activate the hoist contactor which will supply voltage to the motor. A short time
delay is provided before the brake is released. In an overhauling load operation, the hoist contactor
remains activated, providing the motor the opportunity to apply counter-torque in order to maintain the
lowering speed.
In a no-load condition the lower contactor may be energized to operate the drive mechanism against
friction. When full speed lowering is requested the lower contactor closes immediately, the voltage is
ramped to full voltage and the motor will accelerate to full speed.
Bringing the master controller back from full speed to one of the slower speeds will cause additional
counter-torque to be applied until such time that the selected speed is achieved.
In the event that the master controller is brought back to the zero position, additional counter torque
will be applied until the motor reaches zero speed and after a short time delay voltage to the motor is
removed. Should counter-torque braking last for more than the time allowed by the lower plug time
out parameter, the brake will be automatically applied, the voltage removed from the motor and a
fault “Plugg out time” displayed on the drive.
5.4.3.
Regeneration
Selecting full speed when lowering, the THYROMAT will activate the lowering contactors. Voltage is
applied to the motor and after a short delay the brake is released. The motor is then driven at full
speed in the lowering direction.
5.4.4.
Lowering With a Light Load
The lowering operation with light loads is slightly different from the other lowering operations. As
soon as one of the three lowering slow speeds on the master controller is selected, the THYROMAT
will activate the hoist contactors which will supply voltage to the motor, a short delay in time is
provided before the brake is released. Should the motor not move, the hoist contactors will be
