Critical Speeds - ABB ACS355 series User Manual

142 Program features

Critical speeds

Critical speeds function is available for applications where it is necessary to avoid
certain motor speeds or speed bands because of, eg, mechanical resonance
problems. The user can define three critical speeds or speed bands.

Settings
Parameter group 25 CRITICAL SPEEDS
Constant speeds
It is possible to define seven positive constant speeds. Constant speeds are selected
with digital inputs. Constant speed activation overrides the external speed reference.
Constant speed selections are ignored if
• torque control is active, or
• PID reference is being followed, or
• drive is in local control mode.
This function operates on a 2 ms time level.

Settings
Parameter
Group 12 CONSTANT SPEEDS
1207
1208
Additional information
Constant speed settings
Constant speed 6. Used also for jogging function. See
section Jogging on page 162.
Constant speed 7. Used also for fault functions (see group
30 FAULT FUNCTIONS) and for jogging function (see
section Jogging on page 162).