Yaskawa AC Drive Z1000 Bypass Technical Manual - Manual (Page 173)

n L3-25: Load Inertia Ratio
Determines the ratio between the rotor inertia and the load. Set this parameter when using Single Drive KEB 2
(L2-29 = 1 <1> ), Intelligent Stall Prevention during deceleration (L3-04 = 2), or the overvoltage suppression function
(L3-11 = 1).
No. Name Setting Range Default
L3-25 Load Inertia Ratio 0.0 to 1000.0 1.0
When set incorrectly, a fairly large current ripple can result during Single Drive KEB 2 (L2-29 = 1 <1> ). This may cause
overvoltage suppression (L3-11 = 1) or other faults such as ov, Uv1, and oC.
Calculate parameter L3-25 in the formula below:
L3-25 =
Machine Inertia
Motor Inertia
<1> Details on this function can be found in the standard Z1000 Programming Manual (SIEPC71061645) at
www.yaskawa.com.
u L4: Reference Detection
These parameters set up the Loss of Frequency Reference function.
n L4-05: Frequency Reference Loss Detection Selection
The drive can detect a loss of analog frequency reference from input A1 or A2. Frequency reference loss is detected when the
frequency reference drops below 10% of the reference or below 5% of the maximum output frequency within 400 ms.
100%
400 ms
Analog
frequency
reference
Loss of
Reference
output
time
10%
ON OFF
Figure 5.45 Loss of Reference Function
Parameter L4-05 selects the operation when a frequency reference loss is detected.
No. Name Setting Range Default
L4-05 Frequency Reference Loss Detection Selection 0, 1 1
Setting 0: Stop
Drive follows the frequency reference (which is no longer present) and stops the motor.
Setting 1: Continue Operation with Reduced Frequency Reference
The drive will continue operation at the percent of the previous frequency value set to parameter L4-06. When the external
frequency reference value is restored, the operation is continued with the frequency reference.
n L4-06: Frequency Reference at Reference Loss
Sets the frequency reference level at which the drive runs when L4-05 = 1 and when detecting a reference loss. The value is
set as a percentage of the frequency reference before the loss was detected.
No. Name Setting Range Default
L4-06 Frequency Reference at Reference Loss 0.0 to 100.0% 80.0%
5.9 L: Protection Functions
YASKAWA ELECTRIC SIEP YAIZ1B 01D YASKAWA AC Drive – Z1000 Bypass Technical Manual 173
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Programming