YASKAWA Z1000U Series Programming Manual page 115

Setting 1: Decelerate Using C1-02
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.
Setting 2: Decelerate Using C1-04
Same as setting 1 except the drive decelerates at decel time 2 (C1-04).
n L3-06: Stall Prevention Level during Run
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.
on page 101 for details.
No.
L3-06
<1> The upper limit and default values are determined by parameter L8-38, Carrier Frequency Derating Selection.
n
L3-22: Deceleration Time at Stall Prevention during Acceleration
Sets the brief deceleration time used when stalling occurs while accelerating a PM motor. When set to 0, this function is
disabled and the drive decelerates at the selected deceleration time when stalling occurs.
The function is effective only in OLV/ PM control and when parameter L3-01 is set to 1.
No.
L3-22 Deceleration Time at Stall Prevention During Acceleration
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:
• 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 L3-27: Stall Prevention Detection Time
Sets a delay time from when the Stall Prevention level is reached and the actual Stall Prevention function is activated.
No.
L3-27
YASKAWA ELECTRIC SIEP C710636 10C Z1000U HVAC MATRIX Drive Programming Manual
Name
Stall Prevention Level During Run
Name
Name
Name
Stall Prevention Detection Time
Refer to Multi-Function Analog Input Terminal Settings
Setting Range
30 to 150
Setting Range
0.0 to 6000.0 s
Setting Range
0, 1
Setting Range
0 to 5000 ms
1.8 L: Protection Functions
Default
<1> <1>
Default
0.0 s
Default
0
Default
50 ms
1
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