YASKAWA CIMR-ZU A Series Programming Manual page 110

1 8 L Protection Functions
Settin 1 Decelerate Usin C1 2
If the current exceeds the Stall Prevention level set in parameter L3-06, the drive will decelerate at decel time 1 (C1-02). When
the current level drops below the value of L3-06 minus 2% for 100 ms, the drive accelerates back to the frequency reference
at the active acceleration time.
Settin 2 Decelerate Usin C1
Same as setting 1 except the drive decelerates at decel time 2 (C1-04).
L Stall Pre ention Le el durin
Sets the current level to trigger Stall Prevention during run. Depending on the setting of parameter L3-23, the level is
automatically reduced in the constant power range (speed beyond base speed).
The Stall Prevention level can be adjusted using an analog input.
for details.
on page 96
No
L3-06
<1> The upper limit and default values are determined by parameter L8-38, Carrier Frequency Derating Selection.
L 2 Automatic eduction Selection or Stall Pre ention durin
Reduces the Stall Prevention during run level in the constant power range.
No
L3-23 Automatic Reduction Selection for Stall Prevention During Run
Settin Disabled
The level set in L3-06 is used throughout the entire speed range.
Settin 1 Enabled
The Stall Prevention level during run is reduced in the constant power range. The lower limit will be 40% of L3-06.
O er olta e 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)
1. The motor speed will exceed the frequency reference when overvoltage suppression is triggered. Consequently, overvoltage suppression
Note:
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.
L 11 O er olta e Suppression Function Selection
Enables or disables the overvoltage suppression function.
No
L3-11
Settin 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.
11
Name
Stall Prevention Level During Run
Name
Name
Overvoltage Suppression Function Selection
un
Refer to Multi-Function Analog Input Terminal Settings
Settin an e
30 to 150
<1>
un
Settin an e
0, 1
Settin an e
0, 1
De ault
<1>
De ault
0
De ault
0