YASKAWA F7 Programming Manual page 127

L2-04 Momentary Power Loss Voltage Recovery Ramp Time
Setting Range: 0.0 to 5.0 Seconds
Factory Default: Model Dependent
When momentary power loss recovery is enabled (L2-01≠0), a speed search is executed to catch the potentially spinning motor
shaft. As part of the speed search function full voltage is not immediately applied to the motor but is ramped up.
The setting of parameter L2-04 determines the ramp time for increasing the output voltage from zero to maximum voltage
(E1-05).
If a UV1 fault occurs during the current detection speed search function, increase the setting of L2-04.
L2-05 Undervoltage Detection Level
Setting Range: 150 to 210 Vdc (240V Class), 300 to 420 Vdc (480V Class)
Factory Default: 190 Vdc (240V Class), 380 Vdc (480V Class)
The L2-05 parameter sets the DC Bus undervoltage level. The setting of L2-05 affects the voltage at which a UV alarm or a
UV1 fault will occur. If the setting of L2-05 is lowered below the factory default level (190Vdc for a 240Vac drive and 380Vdc
for a 480Vac drive), then an AC Input Reactor must be installed on the input AC line to prevent inrush current from damaging
the Drive's input diodes. An AC Line dip and fast voltage recovery can potentially cause a large inrush current.
L2-06 KEB Deceleration Time
Setting Range: 0.0 to 200.0 sec
Factory Default: 0.0 sec
This parameter sets the time required to decelerate to zero speed when a KEB command is input (H1-0x = 65 or 66).
L2-07 UV Recovery Time
Setting Range: 0.0 to 25.5 sec
Factory Default: 0.0 sec
Sets the time to accelerate to the set speed after recovery from a momentary power loss. If this parameter is set to zero, then
active accelerate time is used instead.
L2-08 KEB Frequency
Setting Range: 0 to 300 %
Factory Default: 100 %
This parameter allows for the setting load inertia ridethru level, as a percentage of output frequency. This setting is used in
conjunction with multi-function digital input set for KEB ridethru (H1-0x = 65 or 66), after momentary power loss. When KEB
frequency constant is set to zero, KEB ridethru functions as normal, to maintain a controlled deceleration rate for the longest
time possible, during momentary power loss. When the KEB frequency is set to any value other than zero, KEB ridethru for
systems use is enabled.
Programming 119