YASKAWA E7N Technical Manual page 155

The following figure demonstrates acceleration when L3-01= "1: General Purpose".
Output
Frequency
Output
Current
The L3-02 parameter is set as a percentage of the Drive rated output current. If the motor capacity is small compared to the
Drive's capacity, or if the motor stalls during acceleration, lower the set value of L3-02.
L3-04 Stall Prevention Selection During Decel
Setting
0 Disabled
1 General Purpose (factory default)
2 Intelligent
3 Stall prev w/R
The stall prevention during deceleration function adjusts the deceleration time in order to prevent OV fault trips during
deceleration. If L3-04= "0: Disabled", 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: General Purpose", then 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, the deceleration will continue down to the Speed Command
level. See figure below.
480 VAC
If L3-01= "2: Intelligent", the intelligent stall prevention is enabled. The active deceleration time is ignored and the Drive will
attempt to decelerate as quickly as possible without causing the DC Bus voltage to exceed the stall prevention level.
The following figure demonstrates acceleration when L3-04= "1 General Purpose".
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a a
Fig 5.31 Time Chart for Stall Prevention During Acceleration
Description
Table 5.16 Stall Prevention During Decel
Drive Voltage
240 VAC
E1-01 ≥ 400 VAC
E1-01 < 400 VAC
Programming 5 - 62
t
b
b
L3-02
TIME
t
Stall Prevention Level during Deceleration
(V)
380
760
660
a - Set accel time
b - Accel time is extended