Yaskawa Z1000 AC Drive HVAC - Manual (Page 234)

u Output Frequency is Not as High as Frequency Reference
Cause Possible Solutions
Frequency reference is set within the range of the Jump
frequency.
• Adjust the parameters used for the Jump frequency function (d3-01, d3-02, d3-03).
• Enabling the Jump frequency prevents the drive from outputting the frequencies specified in
the Jump range.
Upper limit for the frequency reference has been
exceeded.
• 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
Large load triggered Stall Prevention function during
acceleration.
• Reduce the load.
• Adjust the Stall Prevention level during acceleration (L3-02).
u Sound from Motor
Cause Possible Solutions
Exceeded 110% of the rated output current of the drive
while operating at low speeds.
• 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.
u Unstable Motor Speed when Using PM
Cause Possible Solutions
Drive is attempting to operate the motor beyond the
speed control range listed in the specifications.
Check the speed control range and adjust the speed accordingly.
Motor hunting occurs. Refer to Motor Performance Fine-Tuning on page 192 for details.
Hunting occurs at start. Increase the S-curve time at the start of acceleration (C2-01).
Too much current is flowing through the drive.
For special-purpose motors, enter the correct data to all E5 parameters according to the test report
provided for the motor.
u Motor Does Not Restart after Power Loss
Cause Possible Solutions
The Run command was not issued again when power
was restored.
• 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.
The relay that is supposed to maintain the Run
command has been switched off.
Check wiring and circuitry for the relay intended to keep the Run command enabled.
5.10 Troubleshooting without Fault Display
234 YASKAWA ELECTRIC TOEP YAIZ1U 03A YASKAWA AC Drive – Z1000 User Manual