Omron V1000 User Manual page 257

6.9 Troubleshooting without Fault Display
Cause
The Stall Prevention level during
run has been set too low.
Although the drive is operating in
Open Loop Vector motor control
method, Auto-Tuning has not
been performed.
Drive reached the limitations of
the V/f motor control method.
n
Drive Frequency Reference Differs from the Controller Frequency Reference Command
Cause
The analog input frequency gain and bias are set to
incorrect values.
A frequency bias signal is being entered via analog
input terminals A1 or A2.
n Poor Speed Control Accuracy
Cause
Drive reached the slip compensation limit.
Motor-rated voltage is set too high in Open Loop
Vector Control.
Auto-Tuning did not complete properly for Open
Loop Vector Control.
n 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.
Reaching the torque limit.
Load exceeded the internal torque limit determined
by the drive rated current.
n
Motor Hunting Occurs When Operating With a Light Load
Cause
Carrier frequency is too high.
Large V/f setting value at low speeds triggers
overexcitation.
The maximum output frequency and the base
frequency reference are not set properly in
relationship to each other.
Hunting Prevention is disabled (V/f control only).
256
• 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.
• Perform Auto-Tuning.
• Calculate motor data and reset motor parameters.
• Switch to the V/f motor control method (A1-02 = "0").
• 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 main speed frequency reference terminal input gain level assigned to terminals
A1 and A2, as well as the frequency reference input bias to terminals A1 and A2 (parameters
H3-03, H3-04, and H3-12).
• Set these parameters to the appropriate values.
• If multi-function analog input terminals A1 and A2 are set for frequency reference (H3-02
= 0 and H3-10 = 0), the addition of both signals builds the frequency reference.
• Ensure that H3-02 and H3-10 are set appropriately.
• Check the input level set for terminals A1 and A2 (U1-13, U1-14).
• Check the slip compensation limit (C3-03).
• Increase the value set to C3-03.
• The input voltage for the drive determines the maximum output voltage. A drive with an
input of 200 Vac can only output a maximum of 200 Vac. Open Loop Vector Control
sometimes calculates an output voltage reference value that exceeds the maximum drive
output voltage level, resulting in a loss of speed control accuracy.
• Use a motor with a lower voltage rating (a vector control motor).
• Increase the input power voltage.
• Perform Auto-Tuning again.
• Check the Stall Prevention Level during deceleration (L3-04).
• If a braking resistor 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.
• Check the settings for the torque limit (L7-01 through L7-04).
• If the torque limit is enabled, deceleration might take longer than expected because the drive
cannot output more torque than the limit setting. Ensure the torque limit is set to a large
enough value.
• Increase the torque limit setting.
• If multi-function analog input terminal A1 or A2 is set to torque limit (H3-02 or H3-10 equals
10, 11, 12, or 15), ensure that the analog input levels are set to the correct levels.
• Ensure H3-02 and H3-10 are set to the right levels.
• Ensure the analog input is set to the correct value.
Switch to a larger capacity drive.
Lower the carrier frequency setting C6-02.
• Select the proper V/f pattern (E1-03).
• Use parameters E1-04 through E1-10 to set the V/f pattern in relation to the load
characteristics.
Set the proper values for the maximum output frequency and base frequency (E1-04, E1-06).
• Enable Hunting Prevention by setting n1-01 = "1".
• (OLV only) Increase the speed feedback detection control gain and time constant (n2-01,
n2-02).
Possible Solutions
Possible Solutions
Possible Solutions
Possible Solutions
Possible Solutions
SIEP C710606 20 OYMC AC Drive - V1000 User Manual