Group 25: Critical Freq - ABB ACS 400 User Manual

Group 25: Critical Freq

In some mechanical systems, certain speed ranges can cause resonance problems. With this
parameter group, it is possible to set up to two different speed ranges that the ACS 400 will skip over.
Code Description
2501 CRIT FREQ SEL
Critical frequencies activation.
0 =
OFF
1 =
ON
2502 CRIT FREQ 1 LO
Critical frequency 1 start.
Note! If LOW > HI, no critical frequency lock-out will happen.
2503 CRIT FREQ 1 HI
Critical frequency 1 end.
2504 CRIT FREQ 2 LO
Critical frequency 2 start.
2505 CRIT FREQ 2 HI
Critical frequency 2 end.
Note! If LOW > HI, no critical frequency lock-out will happen.
Example: A fan system vibrates badly from 18 Hz to 23 Hz and from 46 Hz to 52 Hz. Set the
parameters as follows:
1 = 18 Hz and
CRIT FREQ LO
2 = 46 Hz and
CRIT FREQ LO
Figure 43 Example of critical frequencies setting in a fan system with bad vibrations at frequency
ranges 18 Hz to 23 Hz and 46 Hz to 52 Hz.
ACS 400 User's Manual
1 = 23 Hz
CRIT FREQ HI
2 = 52 Hz
CRIT FREQ HI
f
output
52
46
23
18
f1L f1H f2L
18 23 46
f (Hz)
REF
f2H
52
83