Hitachi L700 Series, Instruction Manual, Page: 100 / 263

Chapter 4 Explanation of Functions
4 - 38
(a) Reduced-torque characteristic
The time-limit characteristic determined by the value of "b012", "b212", or "b312" is integrated with each
frequency multiplied by reduction scales.
Example) Setting on the L700-185LFF (rated current: 73 A)
When "b012" is 64 A, the base frequency is 60 Hz,
and output frequency is 20 Hz:
(b) Constant-torque characteristic
Make this setting when driving a constant-torque motor with the inverter.
(Example) Setting on the L700-185LFF (rated current: 73A)
When "b012" is 73 A, and output frequency is 2.5 Hz:
(c) Free setting of electronic thermal characteristic
To protect the motor against overheating, you can set the electronic thermal characteristic freely according
to the load on the motor.
The range of setting is shown in the figures below.
Item Function code Range of data Description
Free setting, electronic
thermal frequency (1) (2)
(3)
b015/b017/
b019
0. to 400. (Hz) Setting of frequency at each breakpoint
Free setting, electronic
thermal current (1) (2) (3) b016/b018/
b020
0.0 (A) Disabling the electronic thermal protection
0.1 to rated
current. (A)
Setting of the current at each breakpoint
Trip time (s)
Motor current (A)
(Ratio to the rated
current of inverter)
63.7
(87.2%)
70.1
(120%)
87.6
(160%)
0
60
0.5
X1.0
5 16 50
X0.8
X0.6
0
6
20
60 0
Reduction
scale
Base frequency
Inverter output
frequency (Hz)
Trip time (s)
Motor current (A)
(Ratio to the rated
current of inverter)
X1.0
0 60
X0.9
X0.8
5 2.5
71.6
(98.1%)
78.8
(108%)
98.6
(135%)
60
0.5
0
Reduction
scale
Inverter output
frequency (Hz)
Trip time (s)
Motor current (A)
(Ratio to the rated
current of inverter)