5.7 L: Protection Functions Setting 1: Enabled, with Time Limit When a momentary power loss occurs, the drive will attempt to restart and perform Speed Search if power is restored within a certain period of time. If power is not restored within this time, then a Uv1 fault is triggered and the drive output will be shut off. The allowable time for the momentary power loss condition is dependent on the drive capacity. Setting 2: Recover as Long as CPU has Power Drive will try to restart as long as the CPU still has power. This allows for a longer ride-through time than setting L2-01 to 1. A Uv1 fault is not triggered. Note: 1.
When L2-01 is set to 1 or 2, and a magnetic contactor between motor and drive is used, be sure that the magnetic contactor is kept close as long as the drive attempts to restart. 2. When L2-01 is set to 1 or 2, “Uv” will flash on the operator while the drive is attempting to recover from a momentary power loss. A fault signal is not output at this time. u L3: Stall Prevention When the load is too high or acceleration and deceleration times are too short, the motor may be unable to keep up with the frequency reference, resulting in excessive slip. This “stalling” makes it impossible to decelerate or accelerate.
The drive can prevent the motor from stalling and still reach the desired speed without the user needing to change the acceleration or deceleration time settings. The Stall Prevention function can be set separately for acceleration, operating at constant speeds, and deceleration. n L3-01: Stall Prevention During Acceleration Selection Stall Prevention during acceleration is used when the motor loses speed during acceleration due to a relatively large load. It prevents overcurrent and motor overload (oL1) from occurring. This parameter sets the Stall Prevention method for acceleration. Setting 0: Disabled No Stall Prevention is provided.
If the acceleration time setting is too short, the drive may not be able to accelerate within the set time and the motor may stall. Setting 1: Enabled Enables Stall Prevention during acceleration. When the output current exceeds 85% of the level set in parameter L3-02, the acceleration rate is reduced. The acceleration is stopped when the current exceeds L3-02. Acceleration continues when the current falls below L3-02. The Stall Prevention level is automatically reduced in the field weakening area. Output current L3-02 L3-02 -15% Time Time Figure 5.35 Stall Prevention During Acceleration for Induction Motors n L3-02:
Stall Prevention Level During Acceleration Sets the output current level at which the Stall Prevention during acceleration is activated. 104 SIEP C710606 33A OYMC AC Drive – J1000 User Manual No. Name Setting Range Default L3-01 Stall Prevention Selection during Acceleration 0 to 1 1 Stall Prevention Level During Acceleration equency Controls the output frequency to prevent the motor from stalling