Hitachi L700 Series, Instruction Manual, Page: 155 / 263

Chapter 4 Explanation of Functions
4 - 93
4.2.98 Torque limitation function
The torque limitation function allows you to limit the motor
output torque when "03" (sensorless vector control) is
specified for the V/F characteristic curve selection
(A044/A244).
You can select one of the following four torque limitation modes with the torque limit selection (b040):
1) Quadrant-specific setting mode
In this mode, individual torque limit values to be applied to four quadrants (i.e. forward powering,
reverse regeneration, reverse powering, and forward regeneration) are set as the torque limits 1 to 4
(b041 to b044), respectively.
2) Terminal-switching mode
In this mode, the torque limit values set in the torque limits 1 to 4 (b041 to b044) are switched from one
another according to the combination of the states of torque limit switch terminals 1 and 2 (TRQ1 and
TRQ2) assigned to intelligent input terminals. A single selected torque limit is valid in all operating
states of the inverter.
3) Analog input mode
In this mode, a torque limit value is set by a voltage applied to the control circuit terminal O2. The
voltage range 0 to 10 V corresponds to the torque limit value range 0 to 200%. A single selected torque
limit is valid in all operating states of the inverter.
4) Option (option 1/2) mode
This mode is valid when the option board (SJ-DG) is used. For details on this mode, refer to the
instruction manual for the option board.
If function "40" (TL: whether to enable torque limitation) has been assigned to an intelligent input
terminal, the torque limitation mode selected by the setting of "b040" is enabled only when the TL
terminal is turned on. When the TL terminal is off, torque limit settings are invalid, and the maximum
torque setting is applied as a torque limit. If the TL function has not been assigned to any intelligent
input terminal, the torque limitation mode selected by the setting of "b040" is always enabled.
Each torque limit value used for this function is expressed as a ratio of the maximum torque generated
when the inverter outputs its maximum current on the assumption that the maximum torque is 200%.
Note that each torque limit value does not represent an absolute value of torque. The actual output
torque varies depending on the motor.
If the torque limited (TRQ) signal function is assigned to an intelligent output terminal, the TRQ signal
will turn on when the torque limitation function operates.
Item Function code Data or range of data Description
V/F characteristic curve selection A044/A244 03 Sensorless vector control
Torque limit selection b040
00 Quadrant-specific setting mode
01 Terminal-switching mode
02 Analog input mode
03 Option 1 mode
04 Option 2 mode
Torque limit (1)
b041 0 to 150 (%) Forward powering (in
quadrant-specific setting mode)
Torque limit (2)
b042 0 to 150 (%) Reverse regeneration (in
quadrant-specific setting mode)
Torque limit (3)
b043 0 to 150 (%) Reverse powering (in
quadrant-specific setting mode)
Torque limit (4)
b044 0 to 150 (%) Forward regeneration (in
quadrant-specific setting mode)
Terminal function C001 to C008
40 Whether to enable torque limitation
41 Torque limit switch 1
42 Torque limit switch 2
Terminal function C021 to C025 10 Torque limited signal
(NOTE)<>:applied for 90 to 160kW
A044/A244: V/F characteristic curve selection,
1st/2nd motors
b040: Torque limit selection
b041 to b044: Torque limits (1) to (4)
C001 to C008: Terminal [1] to [8] functions
C021 to C025: Terminal [11] to [15] functions
Related code