ABB ACS355 series, User Manual

Page: 240 / 436

240 Actual signals and parameters
2402 TORQ RAMP
DOWN
Defines the torque reference ramp down time, ie, the
minimum time for the reference to decrease from the
nominal motor torque to zero. 0.00 s
0.00…120.00 s Time 1 = 0.01 s
25 CRITICAL
SPEEDS
Speed bands within which the drive is not allowed to
operate.
2501 CRIT SPEED
SEL
Activates/deactivates the critical speeds function. The
critical speed function avoids specific speed ranges.
Example: A fan has vibrations in the range of 18 to 23 Hz
and 46 to 52 Hz. 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.
OFF
OFF Inactive 0
ON Active 1
2502 CRIT SPEED 1
LO
Defines the minimum limit for critical speed/frequency range
1. 0.0 Hz /
1 rpm
0.0…599.0 Hz /
0…30000 rpm Limit in rpm. Limit in Hz if parameter 9904 MOTOR CTRL
MODE setting is SCALAR: FREQ . The value cannot be
above the maximum (parameter 2503 CRIT SPEED 1 HI ).
1 = 0.1 Hz
/ 1 rpm
2503 CRIT SPEED 1
HI
Defines the maximum limit for critical speed/frequency
range 1. 0.0 Hz /
1 rpm
0.0…599.0 Hz /
0…30000 rpm Limit in rpm. Limit in Hz if parameter 9904 MOTOR CTRL
MODE setting is SCALAR: FREQ . The value cannot be
below the minimum (parameter 2502 CRIT SPEED 1 LO ).
1 = 0.1 Hz
/ 1 rpm
2504 CRIT SPEED 2
LO
See parameter 2502 CRIT SPEED 1 LO . 0.0 Hz /
1 rpm
0.0…599.0 Hz /
0…30000 rpm See parameter 2502 . 1 = 0.1 Hz
/ 1 rpm
All parameters
No.
Name/Value Description Def/FbEq
18
23
46
52
1 Par. 2502 = 18 Hz
2 Par. 2503 = 23 Hz
3 Par. 2504 = 46 Hz
4 Par. 2505 = 52 Hz
1 2 3 4
f
output
(Hz)
f
reference
(Hz)