n L3-25: Load Inertia RatioDetermines 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 DefaultL3-25 Load Inertia Ratio 0.0 to 1000.0 1.0When set incorrectly, a fairly large current ripple can result during Single Drive KEB 2 (L2-29 = 1<1>). This may causeovervoltage suppression (L3-11 = 1) or other faults such as ov, Uv1, and oC.Calculate parameter L3-25 in the formula below:L3-25 = Machine InertiaMotor Inertia<1> Details on this function can be found in the standard Z1000 Programming Manual (SIEPC71061645) atwww.yaskawa.com.u L4: Reference DetectionThese parameters set up the Loss of Frequency Reference function.n L4-05: Frequency Reference Loss Detection SelectionThe drive can detect a loss of analog frequency reference from input A1 or A2. Frequency reference loss is detected when thefrequency reference drops below 10% of the reference or below 5% of the maximum output frequency within 400 ms.100%400 msAnalogfrequencyreferenceLoss ofReferenceoutput time10%ONOFFFigure 5.45 Loss of Reference FunctionParameter L4-05 selects the operation when a frequency reference loss is detected.No. Name Setting Range DefaultL4-05 Frequency Reference Loss Detection Selection 0, 1 1Setting 0: StopDrive follows the frequency reference (which is no longer present) and stops the motor.Setting 1: Continue Operation with Reduced Frequency ReferenceThe drive will continue operation at the percent of the previous frequency value set to parameter L4-06. When the externalfrequency reference value is restored, the operation is continued with the frequency reference.n L4-06: Frequency Reference at Reference LossSets the frequency reference level at which the drive runs when L4-05 = 1 and when detecting a reference loss. The value isset as a percentage of the frequency reference before the loss was detected.No. Name Setting Range DefaultL4-06 Frequency Reference at Reference Loss 0.0 to 100.0% 80.0%5.9 L: Protection FunctionsYASKAWA ELECTRIC SIEP YAIZ1B 01E YASKAWA AC Drive – Z1000 Bypass Technical Manual 1735 Programming
