L3: Stall Prevention - Omron J1000 User Manual

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.
No.
L3-01
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.
n L3-02: Stall Prevention Level During Acceleration
Sets the output current level at which the Stall Prevention during acceleration is activated.
104
Name
Stall Prevention Selection during Acceleration
Output current
Stall Prevention Level
During Acceleration
L3-02
L3-02
-15%
Output frequency
Figure 5.35 Stall Prevention During Acceleration for Induction Motors
Controls the output frequency
to prevent the motor from stalling
Setting Range
0 to 1
Time
Time
SIEP C710606 33A OYMC AC Drive – J1000 User Manual
Default
1