SJ700-2 Instruction Manual NT204DX - Hitachi America, Ltd.

Chapter 4 Explanation of Functions
(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 SJ700-150LFF (rated current: 64 A)
When "b012" is 64 A, the base frequency is 60 Hz,
and output frequency is 20 Hz:
Reduction
scale
X1.0
X0.8
X0.6
0
0
5 16 50
6 20 60
Base frequency
Inverter output
frequency (Hz)
Trip time (s)
60
3.0
0
55.8 76.8 102.4
(87.2%) (120%)(160%)
Trip time (s)
Motor current (A)
(Ratio to the rated
current of inverter)
Motor current (A)
(Ratio to the rated
current of inverter)
(b) Constant-torque characteristic
Make this setting when driving a constant-torque motor with the inverter.
(Example) Setting on the SJ700-150LF (rated current: 64 A)
Reduction
scale
X1.0
When "b012" is 64 A, and output frequency is 2.5 Hz:
Trip time (s)
X0.9
X0.8
60
Inverter output
3.0
0 2.5 5
frequency (Hz)
60
0 62.8 86.4 115.2
(98.1%)(135%)
(180%)
Motor current (A)
(Ratio to the rated
current of inverter)
(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)
Free setting, electronic
thermal current (1) (2) (3)
b015/b017/
b019
b016/b018/
b020
0. to 400. (Hz) Setting of frequency at each breakpoint
0.0 (A) Disabling the electronic thermal protection
0.1 to rated
current. (A)
Setting of the current at each breakpoint
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