Drive Frequency Reference Differs From The Controller Frequency Reference Command; Excessive Motor Oscillation And Erratic Rotation; Deceleration Takes Longer Than Expected With Dynamic Braking Enabled - YASKAWA A1000 HHP Programming Manual

2.10 Troubleshooting without Fault Display
Cause
Incorrect frequency reference setting.
The Stall Prevention level during acceleration and
deceleration set too low.
The Stall Prevention level during run has been set too
low.
Drive reached the limitations of the V/f motor control
method.
u

Drive Frequency Reference Differs from the Controller Frequency Reference Command

Cause
The analog input gain and bias for the frequency
reference input are set to incorrect values.
A frequency bias signal is being entered via analog
input terminals A1 to A3.
PID control is enabled, and the drive is consequently
adjusting the output frequency to match the PID
setpoint. The drive will only accelerate to the
maximum output frequency set in E1-04 while PID
control is active.
u

Excessive Motor Oscillation and Erratic Rotation

Cause
Poor balance between motor phases.
Hunting prevention function is disabled.
u

Deceleration Takes Longer Than Expected with Dynamic Braking Enabled

Cause
L3-04 is set incorrectly.
The deceleration time is set too long.
Insufficient motor torque.
230
• Check the multi-function analog input settings. Multi-function analog input terminal A1, A2,
or A3 is set for frequency gain (H3-02, H3-10, or H3-06 is set to "1"), but there is no voltage
or current input provided.
• Make sure H3-02, H3-10, and H3-06 are set to the proper values.
• See if the analog input value is set to the right value (U1-13 to U1-15).
• Check the Stall Prevention level during acceleration (L3-02).
• If L3-02 is set too low, acceleration may be taking too long.
• Increase L3-02.
• Check the Stall Prevention level during run (L3-06).
• If L3-06 is set too low, speed will drop as the drive outputs torque.
• Increase the setting value.
• The motor cable may be long enough (over 50 m) to require Auto-Tuning for line-to-line
resistance.
• Be aware that V/f Control is comparatively limited when it comes to producing torque at low
speeds.
• Consider switching to Open Loop Vector Control.
• Check the gain and bias settings for the analog inputs that are used to set the frequency reference.
Check parameters H3-03 and H3-04 for input A1, check parameters H3-11, and H3-12 for input
A2, and check parameters H3-07 and H3-08 for input A3.
• Set these parameters to the appropriate values.
• If more than one of multi-function analog inputs A1 to A3 is set for frequency reference bias
(H3-02, H3-10, or H3-06 is set to "0"), then the sum of all signals builds the frequency reference.
• Make sure that H3-02, H3-10, and H3-06 are set appropriately.
• Check the input level set for terminals A1 to A3 (U1-13 to U1-15).
If PID control is not necessary for the application, disable it by setting b5-01 to 0.
Check drive input power voltage to ensure that it provides stable power.
• Enable Hunting Prevention (n1-01 = 1).
• Increase the AFR gain (n2-01) or the AFR time constant 1 (n2-02).
• Check the Stall Prevention level during deceleration (L3-04).
• If a dynamic braking option has been installed, disable Stall Prevention during deceleration
(L3-04 = 0).
Set deceleration to more appropriate time (C1-02, C1-04, C1-06, C1-08).
• Assuming parameter settings are normal and that no overvoltage occurs when there is
insufficient torque, it is likely that the demand on the motor has exceeded the motor capacity.
• Use a larger motor.
YASKAWA ELECTRIC SIEP YEAHHP 01B YASKAWA AC Drive – A1000 HHP Programming Manual
Possible Solutions
Possible Solutions
Possible Solutions
Possible Solutions