Chapter 9 Inverter Functions
9-9-17
9.9.8
Continuing to Drive Even after Instantaneous Power Failure/Undervoltage Error
 How to keep the motor running without shutting off the output after instantaneous power failure
or undervoltage error occurs?
 How to resume operation when the power is restored without shutting off the output after
instantaneous power failure or undervoltage error occurs?
 The non-stop operation during instantaneous power failure function is a function that
decelerates the motor to stop without shutting off the inverter output and without exceeding the
overvoltage level, even when a power interruption occurs during operation.
 Three deceleration stop operation modes can be selected by setting "Instantaneous power
failure non-stop function, mode selection [b050]".
 The "Instantaneous power failure non-stop function, start voltage level [b051]" and the
"Instantaneous power failure non-stop function, target voltage level [b052]" should be equal to
or greater than the undervoltage level (approx. 172.5 VDC for 200 V class and 345 VDC for 400
V class). This function does not operate when there is an undervoltage. Also, set the [b051]
value to be smaller than that of [b052].
 When " Instantaneous power failure non-stop function, mode selection [b050]" is set to either
"Deceleration-stop (01)", "Voltage controlled deceleration-stop (without recovery) (02)", or
"Voltage controlled deceleration-stop (with recovery) (03)" to perform deceleration stop, this
function is not released until the deceleration stop is completed after this function is activated.
When restarting the inverter, confirm that deceleration stop by this function is completed and
the power has returned, turn off the RUN command once, and then turn it on again.
Voltage controlled deceleration-stop (with recovery):
This decelerates the motor to stop while
performing constant DC voltage control.
When the power returns, operation resumes.