Mitsubishi Electric FR-F820-00077 Instruction Manual page 359

Parameters
NOTES The fast-response current limit cannot be set.
To change the stall prevention operation level with the analog signal under PM motor control, set
C16 to C19 or C38 to C41 to calibrate terminal 1 or terminal 4. (Refer to page 5-273.)
To further prevent a trip (Pr. 154)
● When Pr. 154 "Voltage reduction selection during stall prevention operation" = "0, 10", the output
voltage is reduced. By making this setting, an overcurrent trip becomes less likely to occur. Use
this setting when torque reduction does not pose a problem. (Under V/F control, the output
voltage is reduced only during the stall prevention operation is activated.)
● Set Pr. 154 = "10, 11" when the overvoltage protective function (E.OV ) activates during stall
prevention operation in an application with large load inertia. Note that turning OFF the start
signal (STF/STR) or varying the frequency command during stall prevention operation may delay
the acceleration/deceleration start.
Tab. 5-83:
Trip during stall prevention operation (Pr. 874)
● The inverter can be set to trip at activation of stall prevention and stalling of the motor.
● When a high load is applied and the stall prevention is activated, the motor stalls. At this time, if
the rotation speed is lower than 1.5 Hz and the output torque exceeds the level set in Pr. 874 "OLT
level" setting and such a state continues for 3 s, stall prevention stop (E.OLT) is activated and the
inverter output is shut off.
Fig. 5-70:
FR-F800
Pr. 154
0
1 (initial value)
10
11
Settings of parameter 154
Torque
Output torque
Output frequency
Start signal (STF)
Fault signal (ALM)
Trip during stall prevention operation
V/F V/F V/F Magnetic flux Magnetic flux Magnetic flux
E.OC countermeasure
Effective
⎯
Effective
⎯
Stall prevention limit
Pr. 874
1.5 Hz
3 s
E.OLT occurs
(H) Protective function parameter
E.OV countermeasure
⎯
⎯
Effective
Effective
Time
Time
I003025E
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