YASKAWA V1000 Series Technical Manual page 249

Cause
Motor is not producing enough torque in
the V/f motor control method.
Motor is not producing enough torque in
Open Loop Vector Control.
The drive is set for both 2-wire and 3-wire
sequence at the same time.
Motor Rotates in the Opposite Direction from the Run Command
n
Cause
Phase wiring between the drive and motor is incorrect.
The forward direction for the motor is set-up incorrectly.
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.
Motor Rotates in One Direction Only
n
Cause
The drive prohibits reverse rotation.
A Reverse run signal has not been entered, although 3-wire sequence is
selected.
Motor is Too Hot
n
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 tolerance between motor phases.
The motor fan has stopped or is clogged.
Drive Does Not Allow Selection of Rotational Auto-Tuning
n
Cause
The drive is in the incorrect motor control
method for Rotational Auto-Tuning.
YASKAWA ELECTRIC SIEP C710606 18A YASKAWA AC Drive – V1000 Technical Manual (Preliminary)
• Ensure the selected V/f pattern corresponds with the characteristics of the motor being used.
• Set the correct V/f pattern to E1-03.
• When E1-03 = F, increase both the minimum and mid output frequency voltages (E1-08, E1-10).
Increase the frequency reference so that it is higher than the minimum frequency reference (E1-09).
Perform Line-to-Line Resistance Auto-Tuning when using particularly long motor cables.
Increase the torque compensation gain (C4-01).
• Execute Rotational Auto-Tuning.
• If the motor cables are replaced with longer cables after Rotational Auto-Tuning was performed, Auto-Tuning may need to be repeated due to voltage
drop across the line.
• Check if the torque limit parameters have been set too low (L7-01 through L7-04).
• Reset the torque limit back to its default setting (200%).
Increase both the minimum and mid output frequency voltages (E1-08 and E-10).
• The drive is set for a 3-wire sequence when one of parameters H1-03 through H1-07 is set to 0.
• If the drive is supposed to be set up for a 2-wire sequence, then ensure parameters H1-03 through H1-07 are not set to 0.
• If the drive is supposed to be set up for a 3-wire sequence, then H1-oo must be set to 0. Refer to
• Check the motor wiring.
• Switch two motor cables (U, V, and W) to reverse motor direction.
• Connect drive output terminals U/T1, V/T2 and W/T3 in the right order to the corresponding motor terminals U, V, and
W.
Typically, forward is designated as being counterclockwise when looking from the motor shaft (refer to the figure below).
1. Forward Rotating Motor (looking down the motor shaft)
2. Motor Shaft
• 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").
6.9 Troubleshooting Without Fault Display
Possible Solutions
Table 6.2
Possible Solutions
1
2
Possible Solutions
Possible Solutions
Possible Solutions
for additional information.
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