YASKAWA CIMR-VU BA0001 Technical Manual page 302

6.9 Troubleshooting without Fault Display
Cause
The motor is running at almost 0 Hz and the Speed
Search estimated the speed to be in the opposite
direction.
Note: Check the motor specifications for the forward and reverse directions. The motor specifications will vary depending on the manufacturer
of the motor.
n Motor Rotates in One Direction Only
Cause
The drive prohibits reverse rotation.
A Reverse run signal has not been entered, although
3-Wire sequence is selected.
n Motor is Too Hot
Cause
The load is too heavy.
The air around the motor is too hot.
The drive is operating in a vector control mode but
Auto-Tuning has not yet been performed.
Insufficient voltage insulation between motor phases.
The motor fan has stopped or is clogged.
n Drive Does Not Allow Selection of Rotational Auto-Tuning
Cause
The drive is in the incorrect motor control method for
Rotational Auto-Tuning.
n
Motor Hunting Occurs at Low Speeds
Cause
Excessive load inertia in Open Loop Vector Control.
302
• Disable bi-directional search (b3-14 = "0") so that Speed Search is performed only in the
specified direction.
• Check parameter b1-04.
• Set the drive to allow the motor to rotate in reverse (b1-04 = "0").
• Make sure that one of the input terminals S3 to S7 used for the 3-Wire sequence has been set
for reverse.
If the load is too heavy for the motor, the motor will overheat as it exceeds its rated torque value
for an extended period of time.
Keep in mind that the motor also has a short-term overload rating in addition to the possible
solutions provided below:
• Reduce the load.
• Increase the acceleration and deceleration times.
• Check the values set for the motor protection (L1-01, L1-02) as well as the motor rated current
(E2-01).
• Increase motor capacity.
• Check the ambient temperature.
• Cool the area until it is within the specified temperature range.
• Perform Auto-Tuning.
• Calculate the motor value and reset the motor parameters.
• Change the motor control method to V/f Control (A1-02 = "0").
When the motor is connected to terminals U/T1, V/T2, and W/T3, voltage surges occur between
the motor coils and drive switching.
Normally, surges can reach up to three times the drive input power supply voltage (600 V for 200
V class, and 1200 V for 400 V class).
• Use a motor with voltage tolerance higher than the max voltage surge.
• Use a motor designed to work specifically with a drive when using a 400 V class unit.
• Install an AC reactor on the output side of the drive.
Check the motor fan.
• Check if the drive is set to V/f Control by accident (A1-02 = 0).
• Change the motor control method to Open Loop Vector Control (A1-02 = "2").
• Excess load inertia can cause motor hunting in Open Loop Vector Control due to slow motor
response.
• Increase the speed feedback detection control time constant (n2-02) from its default value of
50 ms to an appropriate level between 200 and 1000 ms. Adjust this setting in combination
with n2-03 (Feedback Detection Control Time Constant 2).
YASKAWA ELECTRIC SIEP C710606 18F YASKAWA AC Drive – V1000 Technical Manual
Possible Solutions
Possible Solutions
Possible Solutions
Possible Solutions
Possible Solutions