YASKAWA GA800 Technical Reference page 976

12.9 L: Protection Functions
Note:
• When overvoltage suppression is triggered, the motor speed is more than the frequency reference. Do not use overvoltage suppression for
applications where the frequency reference and the motor speed must align.
• When you use a braking resistor, set L3-11 = 0 [Disabled].
• The overvoltage suppression function is enabled only when you operate immediately below the maximum frequency. Overvoltage
suppression does not increase the output frequency to more than the maximum frequency. Make sure that the motor and machine
specifications are correct for the application, then increase the maximum frequency.
• If there is a sudden increase to a regenerative load, ov can occur.
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L3-01: Stall Prevention during Accel
No.
Name
(Hex.)
L3-01 Stall Prevention during
Accel
(048F)
Note:
When A1-02 = 5 [Control Method Selection = OLV/PM], the setting range is 0 and 1.
Stall prevention during acceleration prevents the stalling and stopping of motors when the drive detects oC
[Overcurrent], oL2 [Drive Overloaded], or oL1 [Motor Overload] when you apply a large load during acceleration or
when you set sudden acceleration times related to load inertia.
0 : Disable
The Stall Prevention function does not operate during acceleration, and acceleration occurs for the set acceleration
time. If the acceleration time is too short, the motor does not fully accelerate during the set time, which causes the
drive to detect oL1 or oL2 and the motor to stop.
1 : Enabled
Enables the Stall Prevention During Acceleration function. Operation is different for different control methods.
• V/f Control, Open Loop Vector Control, or EZ Open Loop Vector Control
When the output current is more than the value set in L3-02 [Stall Prevent Level during Accel], the drive stops
acceleration. The drive stops deceleration when the output current is less than L3-02 - 15%. The Stall Prevention
function level automatically decreases for constant output ranges.
Figure 12.130 Stall Prevention During Acceleration when Using Induction Motors
• Open Loop Vector Control for PM
When the output current is more than L3-02, the drive stops acceleration. When the time set in L3-27 [Stall
Prevention Detection Time] is expired and the output current = L3-02, the drive will start deceleration as specified
by the value set in L3-22 [PM Stall Prevention Decel Time]. The drive starts acceleration again when the output
current is less than L3-02 - 15%. When the time set in L3-27 is expired, the drive starts acceleration again.
976
V/f CL-V/f OLV CLV AOLV
Sets the method of the Stall Prevention During Acceleration.
Description
OLV/PM AOLV/PM CLV/PM EZOLV OLV/PM
YASKAWA SIEPC71061737D GA800 Drive Technical Reference
Default
(Range)
1
(0 - 3)