Machine Protection
6-
51
Detecting Motor Torque
If an excessive load is placed on the machinery (overtorque) or the load is suddenly lightened (undertorque),
you can output an alarm signal to multi-function output terminal M1-M2, P1-PC, P2-PC, P3-C3, or P4-C4.
To use the overtorque/undertorque detection function, set B, 17, 18, 19 (overtorque/undertorque detection NO/
NC) in one of the following constants: H2-01 to H2-05 (multi-function output terminals M1-M2, P1-PC, P2-
PC, P3-C3, and P4-C4 function selection).
The overtorque/undertorque detection level is the current level (Inverter rated output current 100%) in V/f
control, and the motor torque (motor rated torque 100%) in vector control.
Related Constants
Con-
stant
Number
Name
Description
Setting
Range
Factory
Setting
Change
during
Opera-
tion
Control Methods
Display
V/f
V/f
with
PG
Open
Loop
Vector
1
Flux
Vec-
tor
Open
Loop
Vector
2
L6-01
Torque detec-
tion selection
1
0: Overtorque/undertorque
detection disabled.
1: Overtorque detection only with
speed agreement; operation
continues after overtorque
(warning).
2: Overtorque detected
continuously during operation;
operation continues after
overtorque (warning).
3: Overtorque detection only with
speed agreement; output stopped
upon detection (protected
operation).
4: Overtorque detected
continuously during operation;
output stopped upon detection
(protected operation).
5: Undertorque detection only with
speed agreement; operation
continues after overtorque
(warning).
6: Undertorque detected
continuously during operation;
operation continues after
overtorque (warning).
7: Undertorque detection only with
speed agreement; output stopped
upon detection (protected
operation).
8: Undertorque detected
continuously during operation;
output stopped upon detection
(protected operation).
0 to 8
0
No
A
A
A
A
A
Torq Det 1
Sel
L6-02
Torque detec-
tion level 1
Open-loop vector control: Motor
rated torque is set as 100%.
V/f control: Inverter rated current is
set as 100%.
0 to 300
150%
No
A
A
A
A
A
Torq Det 1
Lvl
L6-03
Torque detec-
tion time 1
Sets the overtorque/undertorque
detection time in 1-second units.
0.0 to
10.0
0.1 s
No
A
A
A
A
A
Torq Det 1
Time