Yaskawa F7 Drive User Manual - Manual (Page 124)

Basic Programming 5 - 23
Stall Prevention
L3-04 Stall Prevention During Deceleration Selection
The stall prevention during deceleration function adjusts the deceleration time in order to prevent OV fault trips during
deceleration. If L3-04=0, stall prevention is disabled, and if the load is large and the deceleration time short enough, the Drive
may fault and stop.
If L3-04=1, the standard stall prevention function is enabled. If, during deceleration, the DC Bus voltage exceeds the stall
prevention level (see table below), the Drive will discontinue decelerating and maintain speed. Once the DC Bus voltage has
dropped below the stall prevention level, deceleration will continue. Fig 5.11 demonstrates deceleration when L3-04=1.
Fig 5.11 Stall Prevention
Setting Description
0 Disabled
1 General purpose (Enabled) (factory default)
2 Intelligent stall prevention (Enabled)
3 Stall prevention with DB resistor (Enabled)
Drive Voltage Stall Prevention Level during Deceleration
240Vac 380Vdc
480Vac
E1-01
≥ 400Vac 760Vdc
E1-01
< 400Vac 660Vdc
a b
Output
Frequency
DC Bus
Voltage
a b
a - Set decel time
b - Decel time is extended
380/660/760Vdc
t
t