Yaskawa GPD503 Drive - Manual (Page 39)

2.7 CRITICAL FREQUENCY REJECTION
A. Cn-16: Prohibited Frequency 1
Factory setting (each): 0.0
Cn-17: Prohibited Frequency 2
Cn-18: Prohibited Frequency 3
Range (each): 0.0 to 400.0 Hz
These three constants allow programming of up to three prohibited frequency points for
eliminating problems with resonant vibration of the motor/machine. This feature does not
actually eliminate the selected frequency values, but will accelerate and decelerate the
motor through the prohibited bandwidth.
B. Cn-19: Prohibited Frequency Deadband Factory setting: 1.0
Range: 0.0 to 25.5 Hz
This constant determines the width of the deadband around each selected prohibited
frequency point. The factory setting is
1.0 , which establishes a deadband of ±1.0 Hz.
EXAMPLE:
Vibration encountered between 30.0 and 36.0 Hz.
SOLUTION: Set Cn-16 to 33.0. This is the center of the problem
frequency band.
Set Cn-19 to 3.0. This will cause the GPD 503 to reject all
frequency command values between 30.0 and 36.0 Hz.
A frequency command in the deadband will be converted to the bottom
value of the deadband, e.g. a command of 33 Hz would result in a run
frequency of 30 Hz.
FREQ. CMD
36 Hz
33 Hz
30 Hz
0
Total Deadband = 6.0 Hz
± Cn-19 (3.0 Hz)
OUTPUT FREQUENCY (Hz)
2-8