Thermal Warning Output - Hitachi SJ300 Series Instruction Manual

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.
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.
Trip
time (s)
60
0.5
0
(x)
Thermal Warning Output – Using parameter C061, you can set the threshold from 0 to 100%
of trip level for turning ON the intelligent output [THM] at that level. In this way, the inverter
provides an early warning before the electronic thermal overload trips and turns OFF the output
to the motor.
Opt.
Symbol Function Name
Code
13 THM Thermal Warning
11, 12, 13, 14, 15,
Valid for
AL0 – AL2
outputs:
C061
Required
settings:
Notes:
• The electronic thermal overload function uses
the output current and time to calculate
thermal heating of the motor.
• The thermistor input of the inverter is a
separate function from the electronic thermal
function. You can set a threshold for it to
cause a trip alarm at a particular thermistor
resistance.
Output
current (A)
B020
B018
B016
0
Hz
400
B015 B017 B019 Ax04
(x) = B018 value x 116%
(y) = B018 value x 120%
(z) = B018 value x 150%
A Reduced trip current at (B017) Hz
(y) (z)
Output
State
ON when the electronic thermal calculation
exceeds the set limit
OFF when the electronic thermal calculation is
less than the set limit
Example: (Requires output configuration—
see page 3–53.)
Inverter output
terminal circuit
See I/O specs
on page 4–9.
4–57
SJ300 Inverter
Hz
max. freq.
Description
THM
14 13 11
CM2
15 12
+
RY
–