Motor Rotates After The Drive Output Is Shut Off; Braking); Output Frequency Is Not As High As Frequency Reference; Buzzing Sound From Motor At 2 Khz - YASKAWA T1000A Technical Manual

6.10 Troubleshooting without Fault Display
u Motor Rotates After the Drive Output is Shut Off (Motor Rotates During DC Injection

Braking)

Cause
DC Injection Braking is set too low and the drive cannot decelerate
properly.
The stopping method is set so that the drive coasts to stop.
u Output Frequency is not as High as Frequency Reference
Cause
Upper limit for the frequency reference has been exceeded.
Large load triggered Stall Prevention function during acceleration.
u Buzzing Sound from Motor at 2 kHz
Cause
Exceeded 110% of the rated output current of the drive while
operating at low speeds.
u Unstable Motor Speed when Using PM
Cause
The motor code for the PM motor (E5-01 or T2-02) is set
incorrectly (Yaskawa motors only).
Drive is attempting to operate the motor beyond the speed control
range listed in the specifications.
Motor hunting occurs.
Hunting occurs at start.
Too much current is flowing through the drive.
u Motor Does Not Restart after Power Loss
Cause
The Run command was not issued again when power was restored.
The relay that is supposed to maintain the Run command has been
switched off.
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• Adjust the DC Injection braking settings.
• Increase the current level for DC Injection Braking (b2-02).
• Increase the DC Injection Braking time at stop (b2-04).
Set b1-03 (Stopping Method Selection) to 0 or 2.
• Set the maximum output frequency and the upper limit for the frequency reference to more appropriate values (E1-
04, d2-01).
• The following calculation yields the upper value for the output frequency = E1-04 x d2-01 / 100
• Reduce the load.
• Adjust the Stall Prevention level during acceleration (L3-02).
• If the output current rises too high at low speeds, the carrier frequency is automatically reduced and causes a whining
or buzzing sound.
• If the sound is coming from the motor, disable carrier frequency derating (L8-38 = 0).
• Disabling the automatic carrier frequency derating increases the chances of an overload fault (oL2). Switch to a larger
capacity motor if oL2 faults occur too frequently.
Refer to Motor Performance Fine-Tuning on page 268
Check the speed control range and adjust the speed accordingly.
Refer to Motor Performance Fine-Tuning on page 268
Increase the S-curve time at the start of acceleration (C2-01).
• Enter the correct motor code for the PM motor being used into E5-01.
• For special-purpose motors, enter the correct data to all E5 parameters according to the test report provided for the
motor.
• Check the sequence and wiring that has been set up to enter the Run command.
• A relay should be set up to make sure the Run command remains enabled throughout any power loss.
Check wiring and circuitry for the relay intended to keep the Run command enabled.
YASKAWA ELECTRIC SIEP C710616 30B YASKAWA AC Drive T1000A Technical Manual
Possible Solutions
Possible Solutions
Possible Solutions
Possible Solutions
for details.
for details.
Possible Solutions