SJ700
2
Inverter
Oper
ati
ons
and Monitor
ing
4–53
Constant Torque Characteristic
– Selecting the constant torque characteristic for the example
motor gives the curves below. At 2.5 Hz, the output current is reduced by a factor of 0.9 for
given trip times.
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.
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.
Suppose the electronic thermal setting (B012) is set to 44 Amperes. The graph below shows the
effect of the free setting torque characteristic curve. For example, at (B017) Hz, the output
current level to cause overheating in a fixed time period is reduced to (B018) A. Points (x), (y),
and (z) show the adjusted trip current levels in those conditions for given trip times.
Function
Code
Name
Description
Range
B015 /
B017 /
B019
Free-setting electronic
thermal frequency 1, 2, 3
Data point coordinates for Hz axis
(horizontal) in the free-form curve
0 to 400Hz
B016 /
B018 /
B020
Free setting electronic
thermal current 1, 2, 3
Data point coordinates for Ampere
axis (vertical) in the free-form curve
0.0 = (disable)
0.1 to 1000.
Trip
time (s)
Reduced trip current at 2.5 Hz
Trip current
reduction
factor
x 1.0
x 0.9
x 0.8
0
2.5
5
60
Hz
A
60
0.5
0
82.8
47.8 62.1
104% 135%
180%
Output
current (A)
Setting range
max. freq.
B020
B018
B016
B015 B017 B019 Ax04
Trip current
reduction
factor
Output freq.
x 1.0
x 0.8
0
5
400
Hz
Hz
0
Trip
time (s)
(x) = B018 value x 116%
(y) = B018 value x 120%
(z) = B018 value x 150%
Reduced trip current at (B017) Hz
60
0
0.5
(x)
(y)
(z)
A