Wegner Crane CFW500 series Applications Manual - page 68
Parameters Description
Crane | 68
5 – The load detection time has elapsed, enabling at that moment the slack cable detection.
6 – The load stops lowering because of an external cause, the motor no longer regenerates energy, but it is
driven by the inverter. Because the load has been previously detected, at that moment the slack cable fault
delay time starts elapsing, according to the value adjusted in P1057.
7 – The delay time to generate the fault has elapsed and the fault message “F773: Detected Slack Cable” is
generated. At that moment, the command for closing the brake is executed through the digital output DO1 and
the motor is demagnetized (general disabled).
8 – The load lowering command is removed from the digital input DI2.
9 – The command to reset the inverter is executed through the CFW500 HMI reset key. At that moment, the
drive status changes to “ready”, becoming prepared to receive a new command. The motor remains
demagnetized and the load remains stopped, being held by the mechanical brake.
3.16 INVERTER IN TORQUE LIMIT DETECTION
This parameter group allows the user to adjust the conditions for the crane motion torque limit detection during
the load hoisting/forward or lowering/reverse stages.
Inverter in Torque Limit is an abnormal condition detected in the crane motion operation, when the CFW50
frequency inverter is not able to execute the motion in the desired manner (with controlled speed), i.e., operating
in a torque limit condition.
NOTE!
The inverter in torque limit detection is based on the CFW500 frequency inverter speed control, after
the command to release the brake, i.e., the torque limit detection is not performed with the brake
closed. It is necessary to use sensorless vector or vector with encoder control mode for inverter in
torque limit detection.
P0169 – Maximum Positive Torque Current
P0170 – Maximum Negative Torque Current
Adjustable
0.0 to 350.0 %
Factory Setting: 200.0 %
Range:
Proprieties:
Access groups via HMI:
VETORIAL
Description:
These parameters limit the motor current component that produces positive (P0169) or the negative (P0170)
torque. The adjustment is expressed as a percentage of the rated motor torque current.
NOTE!
In this crane motion application, because of the default definition that the hoisting command is
forward, the lowering command is reverse, and with P1026 disabled, when a hoisting command is
executed the torque polarity is positive, and during a lowering command it is also positive because of
the load braking (the system sends energy to the inverter). The excess of braking energy is dissipated
on the braking resistor.
P1028 – Speed Hysteresis for Inverter in Torque Limit Detection
Adjustable
0.0 to 50.0 %
Factory Setting: 7.5 %
Range:
Proprieties:
Access groups via HMI:
SPLC