YASKAWA Z1000 CIMR-ZU*A Series Programming Manual page 108

1.8 L: Protection Functions
No.
L3-06
<1> The upper limit and default values are determined by parameter L8-38, Carrier Frequency Derating Selection.
n L3-23: Automatic Reduction Selection for Stall Prevention during Run
Reduces the Stall Prevention during run level in the constant power range.
No.
L3-23 Automatic Reduction Selection for Stall Prevention During Run
Setting 0: Disabled
The level set in L3-06 is used throughout the entire speed range.
Setting 1: Enabled
The Stall Prevention level during run is reduced in the constant power range. The lower limit will be 40% of L3-06.
n Overvoltage Suppression Function
Suppresses overvoltage faults by decreasing the regenerative torque limit and slightly increasing the output frequency when
the DC bus voltage rises.
The regenerative torque limit and the output frequency are adjusted during ov suppression so that the DC bus voltage does
not exceed the level set to parameter L3-17. In addition to the parameters explained below, ov suppression also uses these
settings for frequency adjustment:
• DC bus voltage gain (L3-20)
• Deceleration rate calculations gain (L3-21)
• Inertia calculations for motor acceleration time (L3-24)
• Load inertia ratio (L3-25)
Note: 1. The motor speed will exceed the frequency reference when overvoltage suppression is triggered. Consequently, overvoltage suppression
is not appropriate in applications that require a perfect match between the frequency reference and the motor speed.
2. Overvoltage may still occur if there is a sudden increase to a regenerative load.
3. This function is enabled only when operating just below the maximum frequency. Overvoltage suppression does not increase the output
frequency beyond the maximum frequency. If the application requires this, increase the maximum frequency and change the base
frequency setting.
n L3-11: Overvoltage Suppression Function Selection
Enables or disables the overvoltage suppression function.
No.
L3-11
Setting 0: Disabled
The regenerative torque limit and the output frequency are not adjusted. A regenerative load may trip the drive with an
overvoltage fault. Use this setting if dynamic braking options are installed.
Setting 1: Enabled
When the DC bus voltage rises due to regenerative load, an overvoltage fault is prevented by decreasing the regenerative
torque limit and increasing the output frequency.
n L3-17: Target DC Bus Voltage for Overvoltage Suppression and Stall Prevention
Sets the target DC bus voltage level used by the overvoltage suppression function (L3-11 = 1), Intelligent Stall Prevention
during deceleration (L3-04 = 2).
No.
Target DC Bus Voltage for Overvoltage Suppression
L3-17
<1> This value is initialized when E1-01 is changed.
108
Name
Stall Prevention Level During Run
Name
Name
Overvoltage Suppression Function Selection
Name
and Stall Prevention
Setting Range
30 to 150
Setting Range
Setting Range
Setting Range
431.3 to 1150 Vdc
YASKAWA SIEP YAIZ1U 03B YASKAWA AC Drive – Z1000 Programming Manual
Default
<1> <1>
Default
0, 1 0
Default
0, 1 0
Default
1063.8 Vdc
<1>