Stall Prevention Operation (Pr. 22, Pr. 23, Pr. 48, Pr. 66, Pr. 156, Pr. 157, Pr. 277) - Mitsubishi Electric 700 Series Instruction Manual

5.4.5

Stall prevention operation (Pr. 22, Pr. 23, Pr. 48, Pr. 66, Pr. 156, Pr. 157, Pr. 277)

This function monitors the output current and automatically changes the output frequency to prevent the inverter from
coming to trip due to overcurrent, overvoltage, etc. In addition, simple torque limit which limits the output torque to the
predetermined value can be selected.
It can also limit stall prevention and fast-response current limit operation during acceleration/deceleration, driving or
regeneration.
Stall prevention
If the output current exceeds the stall prevention operation level, the output frequency of the inverter is
automatically varied to reduce the output current.
Fast-response current limit
If the current exceeds the limit value, the output of the inverter is shut off to prevent an overcurrent.
Torque limit
The inverter output frequency is controlled so that the output torque (torque current) will not exceed the stall
prevention operation level (motor rated torque is referenced).
Parameter
Name
Number
Stall prevention operation
22∗
level
Stall prevention
operation level
23
compensation factor
at double speed
Second stall prevention
48
operation current
Stall prevention
66 operation reduction
starting frequency
Stall prevention operation
156
selection
157 OL signal output timer
Stall prevention operation
277
current switchover
The above parameters can be set when Pr. 160 User group read selection = "0". (Refer to page 167)
∗ This parameter allows its setting to be changed during operation in any operation mode even if "0 (initial value) or 1" is set in Pr. 77 Parameter write selection.
(1) Block diagram
Pr. 22
Pr. 48
Adjustment of the output torque (current) of the motor
Initial Value
150%
9999
9999
60Hz
0
0s
0
RT
= 0
RT
+
0
-
Output frequency
Pr. 23, Pr. 66
Setting Range
0 Stall prevention operation invalid
Set the current value to start the stall
0.1 to 200%
prevention operation.
The stall operation level can be reduced
0 to 200% when operating at a high speed above the
rated frequency.
9999 Constant according to Pr. 22.
0 Stall prevention operation invalid
0.1 to 200% Second stall prevention operation level
9999 Same level as Pr. 22.
Set the frequency at which the stall
0 to 400Hz prevention operation level starts being
reduced.
Select whether stall prevention operation
0 to 31, 100, 101 and fast-response current limit operation
will be performed or not.
Output start time of the OL signal output
0 to 25s
when stall prevention is activated.
9999 Without the OL signal output
0 Output current is the limit level
Output torque (torque current) is the limit
1
level
Stall prevention operation invalid
Stall prevention operation level
Description
101
5