ABB ACS850 - Critical Speed

Parameters 185
24.06 Torq ramp up Defines the torque reference ramp-up time, i.e. the time for
the reference to increase from zero to the nominal motor
torque.
0.000 … 60.000 s Torque reference ramp-up time. 1000 = 1 s
24.07 Torq ramp down Defines the torque reference ramp-down time, i.e. the time for
the reference to decrease from the nominal motor torque to
zero.
0.000 … 60.000 s Torque reference ramp-down time. 1000 = 1 s
25
25 Critical speed
Sets up critical speeds, or ranges of speeds, that are avoided
due to, for example, mechanical resonance problems.
25.01 Crit speed sel Enables/disables the critical speeds function.
Example: A fan has vibrations in the range of 540 to 690 rpm
and 1380 to 1560 rpm. To make the drive to jump over the
vibration speed ranges:
• activate the critical speeds function,
• set the critical speed ranges as in the figure below.
Disable Critical speeds are disabled. 0
Enable Critical speeds are enabled. 1
25.02 Crit speed1 lo Defines the low limit for critical speed range 1.
Note: This value must be less than or equal to the value of
25.03 Crit speed1 hi.
-30000 … 30000
rpm
Low limit for critical speed 1. 1 = 1 rpm
25.03 Crit speed1 hi Defines the high limit for critical speed range 1.
Note: This value must be greater than or equal to the value of
25.02 Crit speed1 lo.
-30000 … 30000
rpm
High limit for critical speed 1. 1 = 1 rpm
No. Name/Value Description FbEq
540
690
1380
1560
1Par. 25.02 = 540 rpm
2Par. 25.03 = 690 rpm
3Par. 25.04 = 1380 rpm
4Par. 25.05 = 1590 rpm
1234
Motor speed
(rpm)
Drive speed
(rpm)
Drive speed
(rpm)