Hitachi L300P Series Instruction Manual page 182

4–48
Using Intelligent Output Terminals
Constant Torque Characteristic – The left graph below shows the effect of the constant
torque characteristic curve. For example, at 2.5Hz, the output current level to cause overheating
in a fixed time period is reduced by a factor of 0.9. The right graph below shows the reduced
trip current levels in those conditions for given trip times.
Trip current
reduction
factor
x 1.0
x 0.9
x 0.8
0
2.5 5
Free Thermal Characteristic - It is possible to set the electronic thermal characteristic using a
free-form curve defined by three data points, according to the table below.
Function
Name
Code
B015 / Free-setting electronic
B017 / thermal frequency 1, 2, 3
B019
B016 / Free setting electronic
B018 / thermal current 1, 2, 3
B020
The left graph below shows the region for possible free-setting curves. The right graph below
shows an example curve defined by three data points specified by B015 – B020.
Trip current
reduction
factor
x 1.0
x 0.8
Setting range
0
5
Output freq.
Trip
time (s)
60
0.5
Hz 0
60
Reduced trip current at 2.5 Hz
Description
Data point coordinates for Hz axis
(horizontal) in the free-form curve
Data point coordinates for Ampere
axis (vertical) in the free-form curve
Output
current (A)
B020
B018
B016
0
Hz
400
B015 B017 B019 Ax04
A
47.8 62.1 82.8
104% 135% 180%
Range
0 to 400Hz
0.0 = (disable)
0.1 to 1000.
Hz
max. freq.