ABB ACH550 - Full Version - Enervex

ACH550-UH User’s Manual 1-125
Group 25: CRITICAL SPEEDS
This group defines up to three critical speeds or ranges of speeds that are to be
avoided due, for example, to mechanical resonance problems at certain speeds.
Group 25: Critical Speeds
Code Description Range Resolution Default S
2501 CRIT SPEED SEL 0, 1 1 0 (OFF)
Sets the critical speeds function on or off. The critical speed
function avoids specific speed ranges.
0 = OFF – Disables the critical speeds function.
1 = ON – Enables the critical speeds function.
Example: To avoid speeds at which a fan system vibrates
badly:
• Determine problem speed ranges. Assume they are found to
be: 18…23 Hz and 46…52 Hz.
• Set 2501 CRIT SPEED SEL = 1.
• Set 2502 CRIT SPEED 1 LO = 18 Hz.
• Set 2503 CRIT SPEED 1 HI = 23 Hz.
• Set 2504 CRIT SPEED 2 LO = 46 Hz.
• Set 2505 CRIT SPEED 2 HI = 52 Hz.
2502 CRIT SPEED 1 LO 0.0…500.0 Hz / 0.1 Hz / 0.0 Hz /
0…30000 rpm 1 rpm 0 rpm
Sets the minimum limit for critical speed range 1.
• The value must be less than or equal to 2503 CRIT SPEED 1 HI.
• Units are rpm, unless 9904 MOTOR CTRL MODE = 3 (SCALAR:FREQ), then units are Hz.
2503 CRIT SPEED 1 HI 0.0…500.0 Hz / 0.1 Hz / 0.0 Hz /
0…30000 rpm 1 rpm 0 rpm
Sets the maximum limit for critical speed range 1.
• The value must be greater than or equal to 2502 CRIT SPEED 1 LO.
• Units are rpm, unless 9904 MOTOR CTRL MODE = 3 (SCALAR:FREQ), then units are Hz.
2504 CRIT SPEED 2 LO 0.0…500.0 Hz / 0.1 Hz / 0.0 Hz /
0…30000 rpm 1 rpm 0 rpm
Sets the minimum limit for critical speed range 2.
• See parameter 2502.
2505 CRIT SPEED 2 HI 0.0…500.0 Hz / 0.1 Hz / 0.0 Hz /
0…30000 rpm 1 rpm 0 rpm
Sets the maximum limit for critical speed range 2.
• See parameter 2503.
2506 CRIT SPEED 3 LO 0.0…500.0 Hz / 0.1 Hz / 0.0 Hz /
0…30000 rpm 1 rpm 0 rpm
Sets the minimum limit for critical speed range 3.
• See parameter 2502.
2507 CRIT SPEED 3 HI 0.0…500.0 Hz / 0.1 Hz / 0.0 Hz /
0…30000 rpm 1 rpm 0 rpm
Sets the maximum limit for critical speed range 3.
• See parameter 2503.
52
46
23
18
f output
f1L
18
f1H
23
f2L
46
f2H
52
f REF (Hz)
Parameters