undervoltage trip. If an undervoltage trip occurs, increase the b054 value or decrease the
b053 value.
Main circuit P-N voltage
[V]
b052
b051
Undervoltage level
Output frequency
[Hz]
Time [s]
Time [s]
If a momentary power interruption occur during operation, or if the main circuit DC voltage drops, these
settings will cause the inverter to decelerate with the DC voltage in the main circuit kept at the level set
in the Deceleration Hold Level on Power Interruption (b052).
This function is activated when all of the following start conditions are met:
•
b050 = 02 or 03
•
During RUN (Disabled during trip, during undervoltage, and during stop)
•
The main circuit DC voltage drops to the Starting Voltage on Power Interruption (b051) level or lower.
If the power interruption duration is short, the function allows the inverter to decelerate and stop without
shutting off its output, so the main circuit DC voltage can be kept constant. However, if the power inter-
ruption causes an undervoltage trip, the inverter will shut off its output immediately, so the process of this
function will be terminated. The subsequent operation when the power is restored after a momentary
power interruption depends on the Power Interruption/Undervoltage Restart Selection (b001) setting.
When b050 is set to 03, if the power interruption state is canceled and the incoming voltage is restored before
the occurrence of an under voltage trip, the inverter can recover normal operation. However, this function may
cause deceleration stop depending on the b052 setting. Refer to the table and operation examples below.
If the inverter makes a deceleration stop as a result of this function, it force-terminates the FW (For-
ward) signal even if this signal is ON. To restart the inverter, make sure that the incoming voltage is
recovered and then turn ON the FW (Forward) signal again.