Mitsubishi MR-J4-40A

11. OPTIONS AND AUXILIARY EQUIPMENT
11 - 79
(2) Selection example
Indicated below is an example of selecting an earth-leakage current breaker under the following
conditions.
Servo motor
HG-KR43
2 mm
2
× 5 m2 mm
2
× 5 m
M
NV
Ig1 Iga Ig2 Igm
Servo amplifier
MR-J4-40A
Use an earth-leakage current breaker designed for suppressing harmonics/surges.
Find the terms of equation (11.1) from the diagram.
Ig1 = 20 •
5
1000
= 0.1 [mA]
Ig2 = 20 •
5
1000
= 0.1 [mA]
Ign = 0 (not used)
Iga = 0.1 [mA]
Igm = 0.1 [mA]
Insert these values in equation (11.1).
Ig ≥ 10 • {0.1 + 0 + 0.1 + 1 • (0.1 + 0.1)}
≥ 4 [mA]
According to the result of calculation, use an earth-leakage current breaker having the rated sensitivity
current (Ig) of 4.0 [mA] or more.
An earth-leakage current breaker having Ig of 15 [mA] is used with the NV-SP/SW/CP/CW/HW series.