Load Speed Control - ABB ACS800 Firmware Manual

Load speed control

This function is used for running the motor above the base speed if the motor is able
to provide a sufficient torque with respect to the load condition. The function allows
you to run the motor at a higher speed above the base speed according to the motor
current at the base speed with the load. It is assumed that the load at which the
motor crosses the base speed remains constant until the motor stops, and then a
new Start command is given.
The user defines a set of current (A) and speed (rpm) parameters, which specify the
curve to be used to calculate the motor speed limit according to the current at the
base speed Par. 77.20. The motor current at the base speed Par.
for a predefined time period of Par.
would have settled down to a less oscillating value.
Parameter
Load speed control function. Parameter
after which the motor has crossed the base speed to check for the motor current.
This motor current after this time period delay is regarded by the function as the
base speed current for the particular load used. Parameters
base speed versus current graph in both the forward and reverse direction and are
further used to limit the speed according to the base speed current.
If parameters
speed is always limited to Par.
bit 10) is set to 1. Parameters
• The current values for the forward direction to be entered in parameters 77.04,
77.06, 77.08
• The speed limit values for the forward direction to be entered in parameters
77.05,
• The current values for the reverse direction to be entered in parameters 77.12,
77.14, 77.16
• The speed limit values for the reverse direction to be entered in parameters
77.13,
77.01 LOAD SPD CTRL SEL defines the activation command for the
77.04...77.19 are not configured properly in the correct sequence, the
77.04...77.19
and 77.10 have to be entered in the increasing order.
77.07, 77.09 and 77.11
and 77.18 have to be entered in the increasing order.
77.15, 77.17 and 77.19
77.03 HOLD RAMP, so that the motor current
77.03 HOLD RAMP defines the time period
77.20 BASE SPEED, and the error bit (signal
are to be configured as follows:
have to be entered in the decreasing order.
have to be entered in the decreasing order.
123
77.20 is checked
77.04...77.19 plot the
03.32
Program features