Omron VARISPEED F7 User Manual page 230

Set the Torque Limit Value Using an Analog Input
The analog input A2 can be used to input several torque limits. The table below shows the possible analog
input settings (H3-09) for the torque limit function.
Set
Function
Value
10 Positive torque limit
11 Negative torque limit
12 Regenerative torque limit
15 Positive/negative torque limit
The analog input terminal A2 signal level is factory-set as follows: 4 to 20 mA (i.e. if 20 mA are input the
torque is limited to 100% of the motor rated torque).
its.
Regenerative torque limit
Reverse operation
Negative torque limit
Setting Torque Limits Using Parameters and an Analog Input Together
The following block diagram shows the relationship between torque limit using parameters (L7-01 to L7-04)
and torque limit using the analog input A2.
Multi-function analog input
Terminal
Forward torque limit
A2
(set value = 10)
Negative torque limit
(set value = 11)
Regenerative torque limit (set
value = 12)
Positive/negative torque limit (set
value = 15)
Forward torque limit (L7-01)
Reverse torque limit (L7-02)
Parameters
Forward regenerative torque
limit (L7-03)
Reverse regenerative torque
limit (L7-04)
Fig 6.50 Torque Limit Using Parameters and an Analog Input Together
Enabling Integral Torque Limit Operation (L7-06 and L7-07)
In Open Loop Vector control an integral operation can be applied to the torque limit function (P-control is
standard). This improves the torque limit accuracy and smoothes the torque limit operation. To enable the inte-
gral operation set parameter L7-07 to 1. The integral time constant can be set in parameter L7-06.
100% of Contents
Motor rated torque
Motor rated torque
Motor rated torque
Motor rated torque
Fig 6.49
Output torque
Positive
Negative
Fig 6.49 Torque Limits using the Analog Input
Positive forward drive
torque
Reverse
drive reverse
torque
175% of Inverter rated current
Control Methods
V/f
V/f with
PG
No No
No No
No No
No No
shows the relationship between the torque lim-
Positive/negative torque limits
Forward torque limit
No. of motor rotations
Forward operation
Regenerative torque limit
Positive/negative torque limits
Reverse positive regenerative torque
Forward negative regenerative torque
Min: Minimum value priority circuit
Forward torque limit
Reverse torque limit
Forward regenerative
torque limit
Reverse regenerative
torque limit
Open Closed
Loop Loop
Vector Vector
Yes Yes
Yes Yes
Yes Yes
Yes Yes
6
47
6-