• When a high load is applied and the stall prevention is activated, the motor stalls. At this time, if a state where the motor
rotation speed is lower than 1.5 Hz and the output torque exceeds the level set in Pr.874 OLT level setting continues for
3 seconds, the stall prevention stop (E.OLT) is activated and the inverter output is shut off.
NOTE
• Under V/F control or Advanced magnetic flux vector control, if the output frequency drops to 0.5 Hz due to the stall prevention
operation and this state continues for 3 seconds, a fault indication (E.OLT) appears, and the inverter output is shut off. This
operation is activated regardless of the Pr.874 setting.
CAUTION
• Do not set the stall prevention operation current too low.
Doing so will reduce the generated torque.
• Be sure to perform the test operation.
Stall prevention operation during acceleration may extend the acceleration time.
Stall prevention operation during constant-speed operation may cause sudden speed changes.
Stall prevention operation during deceleration may extend the deceleration time.
Parameters referred to
Pr.73 Analog input
selectionpage 330
Pr.178 to Pr.189 (Input terminal function
Pr.190 to Pr.196 (Output terminal function
Pr.858 Terminal 4 function assignment, Pr.868 Terminal 1 function
280
5. PARAMETERS
5.7 (H) Protective function parameter
Torque
Pr.874
Output torque
Output
frequency
1.5Hz
Start signal
(STF)
Fault signal
(ALM)
selection)page 355
selection)page 312
assignmentpage 334
Stall prevention limit
Time
Time
3s
E.OLT occurs