Yaskawa Z1000U HVAC Matrix Bypass - Manual (Page 185)

n L3-03: Stall Prevention Limit during Acceleration
The Stall Prevention level is automatically reduced when the motor is operated in the constant power range. L3-03 sets the
lower limit for this reduction as a percentage of the drive rated current.
No. Name Setting Range Default
L3-03 Stall Prevention Limit during Acceleration 0 to 100% 50%
Stall Prevention level during Acceleration
Output frequency
L3-03
E1-06
Base frequency
L3-02
Figure 5.41 Stall Prevention Level and Limit During Acceleration
n L3-04: Stall Prevention Selection during Deceleration
Stall prevention during deceleration prevents the motor from stalling when a large load is imposed on the motor or rapid
deceleration is performed.
No. Name Setting Range Default
L3-04 Stall Prevention Selection During Deceleration 0, 1, 4, 6 1
Setting 0: Disabled
The drive decelerates according to the set deceleration time. High inertia loads or rapid deceleration may trigger an overcurrent
(oC) fault. Switch to another L3-04 selection if an oC fault occurs.
Setting 1: General-purpose Stall Prevention
The drive tries to decelerate within the set deceleration time. The drive pauses deceleration when the output current exceeds
the Stall Prevention level and then continues deceleration when the output current drops below that level. Stall Prevention
may be triggered repeatedly to avoid an overcurrent (oC) fault.
Figure 5.42 illustrates the function of Stall Prevention during deceleration.
Output Frequency
Deceleration characteristics
when Stall Prevention was
triggered during deceleration
Time
specified deceleration time
Figure 5.42 Stall Prevention During Deceleration
Setting 4: Overexcitation Deceleration
Overexcitation Deceleration (increasing the motor flux) is faster than deceleration with no Stall Prevention (L3-04 = 0). Setting
4 changes the selected decel time and functions to provide protection from an overvoltage trip.
Setting 6: Enable (Current Limit)
The deceleration rate is automatically adjusted during deceleration of the load while limiting the regeneration current at the
setting value of the stall prevention level during deceleration (L3-14).
The stall prevention level may be reached if an external force is applied in the regeneration direction, dramatically decreasing
the possibility of stopping the motor.
5.8 L: Protection Functions
YASKAWA SIEP YAIZ1D 01A Z1000U HVAC MATRIX Drive Bypass Technical Manual 185
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Programming