Figure 5.36 illustrates the function of Stall Prevention during deceleration.Output FrequencyDeceleration characteristicswhen Stall Prevention wastriggered during decelerationTimespecified deceleration timeFigure 5.36 Stall Prevention During DecelerationSetting 4: Overexcitation DecelerationEnables overexcitation deceleration. Overexcitation Deceleration (increasing the motor flux) shortens the deceleration timecompared to deceleration with no Stall Prevention (L3-04 = 0). Repetitive or long overexcitation deceleration can result inmotor overheat. In such situations, either shorten the deceleration time setting or use a braking resistor option.Use parameter n3-13 to fine-tune this function.Note: Because the allowable flux level for overexcitation varies based on the flux saturation characteristics of the motor, set the properoverexcitation level by adjusting the excitation gain in parameter n3-13. Motor characteristics and inertia of the machine influence thedeceleration time during overexcitation deceleration.n L3-05: Stall Prevention Selection During RunStall Prevention During Run can prevent a motor from stalling by automatically reducing the speed when a transient overloadoccurs while the motor is running at constant speed.This parameter selects the Stall Prevention During Run method.No. Name Setting Range DefaultL3-05 Stall Prevention Selection During Run 0 to 2 1Note: When output frequency is 6 Hz or less, Stall Prevention During Run is disabled regardless of the setting in L3-05/06.Setting 0: DisabledDrive runs at the set frequency reference. A heavy load may cause the motor to stall and trip the drive with an oC or oL fault.Setting 1: Decelerate Using C1-02If the current exceeds the Stall Prevention level set in parameter L3-06, the drive decelerates at Decel Time 1 (C1-02). Oncethe current level drops below the value of L3-06 minus 2% for 100 ms it accelerates back to the frequency reference at theactive acceleration time.Setting 2: Decelerate Using C1-04Same as setting 1 except the drive decelerates at decel time 2 (C1-04).n L3-06: Stall Prevention Level During RunSets the current level for Stall Prevention During Run.No. Name Setting Range DefaultL3-06 Stall Prevention Level During Run 30 to 150 <1> <1><1> The upper limit and default for this setting is determined by C6-01 and L8-38.u L4: Speed AgreeThese parameters set up the speed agree and speed detection functions which can be assigned to the multi-function outputterminal MA-MB-MC.n L4-01: Speed Agreement Detection LevelParameter L4-01 sets the detection level for the digital output functions “Speed Agree”, “Frequency Detection 1”, and“Frequency Detection 2”.5.7 L: Protection Functions116 YASKAWA ELECTRIC SIEP C710606 31B YASKAWA AC Drive – J1000 Technical Manualhttp://nicontrols.com
