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10 OPTIONS AND PERIPHERAL EQUIPMENT
10.6 Earth-leakage current breaker
Selection example
This section shows examples of selecting an earth-leakage current breaker under the following conditions.
Use an earth-leakage current breaker designed for suppressing harmonics/surges.
Find each term of formula (10.1) from the diagram.
Ign = 0 (not used)
Iga = 5 [mA]
Igm = 2.5 [mA]
Insert these values in formula (10.1).
Ig
≥
10 • {0.475 + 0 + 5 + 1 • (0.525 + 2.5)}
Ig
≥
85 [mA]
According to the result of calculation, use an earth-leakage current breaker with a rated sensitivity current (Ig) of 85 mA or
more.
Use 200 mA for the NV-SV/NV-SVF/NV-SW/NV-CV/NV-CVF/NV-CW/NV-HV series.
NV
22 mm
2
× 5 m
30 mm
2
× 5 m
M
Ig1
Ig2
Igm
Iga
Converter
unit
Drive unit
Servo motor
5
1000
Ig1 = 95 •
= 0.475 [mA]
5
1000
Ig2 = 105 •
= 0.525 [mA]
