omron — L3: Stall Prevention

5.7 L: Protection Functions The upper limit and default value is determined by the duty rating and the carrier frequency derating selection (C6-01 and L8-38 respectively). If stalling occurs with L3-02 set to its default value when using a motor that is relatively small compared to the drive, try lowering L3-02. n L3-04: Stall Prevention During Deceleration Selection Stall Prevention during deceleration can control the deceleration based on the DC bus voltage and prevent an overvoltage fault caused by high inertia or rapid deceleration. Selects the Stall Prevention method during deceleration. Setting 0:

Disabled When this setting is used, the drive decelerates according to the set deceleration time. With high inertia loads or rapid deceleration, an overvoltage (ov) fault may occur. In this case use braking options or switch to another L3-04 selection. Setting 1: General Purpose Stall Prevention With this setting the drive tries to decelerate in the set deceleration time. When the DC bus voltage exceeds the Stall Prevention level, the drive pauses deceleration. Deceleration continues as soon as the DC bus voltage drops below that level. Stall Prevention may be triggered repeatedly to avoid an overvoltage fault.

The DC bus voltage level for Stall Prevention depends on the input voltage setting E1-01. Note: Use this setting whenever a Dynamic Braking Resistor or another braking option is used. Note: 1. This setting should not be used in combination with a Dynamic Braking Resistor or other braking options. If Stall Prevention during deceleration is enabled, it will be triggered before the braking resistor option can operate. 2. This method may lengthen the total deceleration time compared to the set value. If this is not appropriate for the application consider using a braking option. Figure 5.36 illustrates the function of Stall Prevention during deceleration.

Output Frequency Time Parameter Details specified deceleration time Figure 5.36 Stall Prevention During Deceleration Setting 4: Overexcitation Braking Enables overexcitation deceleration. Overexcitation Braking (increasing the motor flux) shortens the deceleration time compared to deceleration with no Stall Prevention (L3-04 = 0). Repetitive or long overexcitation deceleration can result in motor 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. 5 Note:

Because the allowable flux level for overexcitation varies based on the flux saturation characteristics of the motor, set the proper overexcitation level by adjusting the excitation gain in parameter n3-13. Motor characteristics and inertia of the machine influence the deceleration time during overexcitation deceleration. n L3-05: Stall Prevention Selection During Run Stall Prevention During Run can prevent a motor from stalling by automatically reducing the speed when a transient overload occurs while the motor is running at constant speed. This parameter selects the Stall Prevention During Run method. SIEP C710606 33A OYMC AC Drive – J1000 User Manual 105 No.

Name Setting Range Default L3-02 Stall Prevention Level during Acceleration 0 to 150% No. Name Setting Range Default L3-04 Stall Prevention Selection During Deceleration Selection 0, 1, 4 1 Drive Input Voltage Stall Prevention Level during Deceleration 200 V Class Vdc = 380 V 400 V Class E1-01 ≥ 400 V Vdc = 760 V E1-01 Vdc = 660 V Deceleration characteristi when Stall Prevention wa triggered during decelera