Overload Limit - Omron SYSDRIVE MX SERIES User Manual

4-2 Function Mode
Overload Limit/Overload Warning
This function helps prevent an overcurrent trip due to rapid load fluctuation in acceleration or
constant speed operation.
Parameter No.
b021
b221
b022
4
b222
b023
b223
b028
b228
C041
C241
Related functions
* To switch to the 2nd control, allocate 08 (SET) to the multi-function input and then turn it on.

Overload Limit

•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.
•This function prevents an overcurrent trip caused by inertia moment during acceleration, or caused
by rapid load fluctuations during constant speed operation.
•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.
•With the overload limit parameter set too low, an overvoltage trip may occur due to regenerative
energy from the motor. This is because of automatic deceleration from this function even during
acceleration.
•Make the following adjustments if this function operates during acceleration and the frequency
doesn't reach the target level.
4-29
Function name
00: Disabled
Overload limit selection
01: Enabled in acceleration/constant
*2nd overload limit
selection
02: Enabled in constant speed operation
Overload limit level
0.1 × Rated current to 1.5 × Rated current
*2nd overload limit level
Overload limit parameter 0.1 to 3000.0
(Deceleration time while this function is in
*2nd overload limit
operation)
parameter
Overload limit source
selection
00: b022, b222 set values
01: Input terminal FV
*2nd overload limit source
selection
0.0: Does not operate.
Overload warning level
0.1 × Rated current to 2.0 × Rated current
(Outputs OL signal when reaching the
*2nd overload warning
level overload warning level.)
• Increase the acceleration time.
• Increase the torque boost.
• Increase the overload limit level.
• Use a higher rank Inverter.
Data
speed operation
C021 to C022, C026
Default setting Unit

01

01
1.5 × Rated
A
current
1.5 × Rated
A
current
1.0 s
1.0 s

00

00
Rated current
A
Rated current