4-2 Function Mode Reduced Torque Characteristics 2 •Multiplied by the time limit characteristics set in b012/212 for each frequency. (Example) 3G3JX-A2007 (Rated current: 4.0 A), b012 = 4.00 (A), Output frequency = 40 Hz Electronic thermal level Time before trip (s) X1.0 X0.8 60 0 20 60 Inverter output frequency (Hz) 4 Motor current (A) (Ratio to the rated current of the Inverter) 4 0 4.16 (104%) 5.4 (135%) 7.2 (180%) Overload Limit/Overload Warning Functions This function helps prevent an overcurrent trip due to rapid load fluctuation in acceleration or constant speed operation. * To switch to the 2nd control, allocate 08 (SET) to the multi-function input terminal and then turn it on.
•The Inverter monitors the motor current during acceleration or constant speed operation. If it reaches the overload limit level, the output frequency is lowered automatically according to the overload limit parameter. •The overload limit level sets a current value for this function to work. •When this function operates, the acceleration time becomes longer than the set time. 4-31 Parameter No. Function name Data Default setting Unit b021 Overload limit selection 00: Disabled 01: Enable in acceleration/constant speed operation 02:
Enabled in constant speed operation 01 ⎯ * b221 2nd overload limit selection 01 ⎯ b022 Overload limit level 0.1 × Rated current to 1.5 × Rated current 1.5 × Rated current A * b222 2nd overload limit level 1.5 × Rated current A b023 Overload limit parameter 0.1 to 3000.0 (Deceleration time while this function is in operation) 1.0 s * b223 2nd overload limit parameter 1.0 s b028 Overload limit source selection 00: b022, b222 set values 01: Input terminal FV 00 ⎯ * b228 2nd overload limit source selection 00 ⎯ C041 Overload warning level 0.0: Does not operate.
0.1 × Rated current to 2.0 × Rated current (Outputs OL signal when the overload warning level is reached.) Rated current A * C241 2nd overload warning level Rated current Related functions C021, C026