Mitsubishi Electric FR-A700 Technical Manual page 117

(4) Electronic thermal relay function operation characteristic (THT)
This electronic thermal relay function operates to protect output transistor in an inverter. Characteristic of the electronic
thermal relay function is determined by the inverter, and cannot be changed with parameters.
Electronic thermal relay function (transistor protection thermal) operation characteristics of
the motor current to the inverter rated current is presented in horizontal axis. Horizontal axis is calculated as follows:
(motor current [A]/inverter rated current [A]) x 100 [%]).
Optimum Conditions
Running frequency : 1Hz or more
Carrier frequency: 2kHz
Running frequency : 1Hz or less
Carrier frequency: 2kHz
55K or less
150
120
90
F 700
60
30
0
0 25 50 75 100 125 150 175 200
Ratio of the motor current
to the inverter rated current (%)
15
12
9
F 700
6
3
0
0 25 50 75 100 125 150 175 200
Ratio of the motor current
to the inverter rated current (%)
110
common
A700 F700
150
120
A700
90
60
30
0
0 25
to the inverter rated current (%)
15
A700
12
9
6
3
0
0 25
Ratio of the motor current
to the inverter rated current (%)
SPECIFICATIONS
when the ratio of
A700 F700
75K or more
A700
F 700
50 75 100 125 150 175 200
Ratio of the motor current
A700
F 700
50 75 100 125 150 175 200