YASKAWA GA800 Programming Manual page 455

The stall prevention level set in L3-02 [Stall Prevent Level during Accel] is automatically reduced when the motor is
running within the constant output range. Parameter L3-03 is the limit value used to prevent the stall prevention level
during constant output ranges to fall below the minimum required level.
Note:
The function to automatically reduce the stall prevention level does not operate when L3-01 = 3 [Stall Prevention during Accel = Current
Limit Method].
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L3-04: Stall Prevention during Decel
No.
Name
(Hex.)
L3-04 Stall Prevention during
Decel
(0492)
Note:
1. To connect a dynamic braking option (braking resistor or braking resistor unit) to the drive, set this parameter to 0 or 3. Parameter values
1, 2, 4, and 5 will enable Stall Prevention function during deceleration, and the dynamic braking option will not function.
2. The setting range changes when the A1-02 [Control Method Selection] value changes:
• When A1-02 = 5 [OLV/PM], the setting range is 0 to 2.
• When A1-02 = 6, 7, 8 [AOLV/PM, CLV/PM, EZOLV], the setting range is 0, 1.
Stall Prevention during deceleration controls the deceleration as specified by the DC bus voltage and does not let high
inertia or fast deceleration cause ov [Overvoltage] faults.
0 : No
The drive decelerates as specified by the deceleration time. If the deceleration time is too short, the drive can detect an
ov fault.
Note:
If an ov fault occurs, connect a dynamic braking option to the drive. If an ov fault occurs after you connect a dynamic braking option and A1-
02 = 0 or 2 [Control Method Selection = V/f or CLV] and L3-04 = 0, set L3-04 = 3.
1 : General Purpose
The drive decelerates as specified by the deceleration time. When the DC bus voltage is more than the Stall
Prevention level, the drive stops deceleration until the DC bus voltage is less than the Stall Prevention Level. The
drive then starts to decelerate at the set deceleration time. Frequent use of Stall Prevention will help prevent ov faults
when the deceleration time is shorter than the drive can usually accept.
Note:
The Decel Stall Prevention function will increase the deceleration time to stop and the deceleration time will be longer than the setting. This
function is not applicable for conveyor applications because the precision of the stop position is very important. As an alternative, use a
dynamic braking option in these applications.
The input voltage setting of E1-01 [Input AC Supply Voltage] sets the DC bus voltage level for Stall Prevention.
Drive Input Voltage
200 V class
400 V class
YASKAWA TOEPYAIGA8002B GA800 Drive Programming
Figure 2.133 Stall Prevent Level during Accel/Limit
V/f CL-V/f OLV CLV AOLV
Sets the method that the drive will use to prevent overvoltage faults when decelerating.
Table 2.68 Stall Prevention Level during Deceleration
Description
OLV/PM AOLV/PM CLV/PM EZOLV OLV/PM
Stall Prevention Level during Deceleration
377 V
754 V
2.9 L: Protection Functions
Default
(Range)
1
(Determined by A1-02)
2
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