Earth-Leakage Current Breaker - Mitsubishi Electric MELSERVO-J4 Series Instruction Manual

11.15

Earth-leakage current breaker

Selection method
High-frequency chopper currents controlled by pulse width modulation flow in the AC servo circuits. Leakage currents
containing harmonic contents are larger than those of the motor which is run with a commercial power supply.
Select an earth-leakage current breaker according to the following formula, and ground the servo amplifier, servo motor, etc.
securely.
To minimize leakage currents, make the input and output wires as short as possible, and keep a distance of 30 cm or longer
between the wires and ground.
Rated sensitivity current  10 • {Ig1 + Ign + Iga + K • (Ig2 + Igm)} [mA]    (11.1)
Cable
NV Noise filter
Cable
Servo
amplifier
Ig1 Ign Iga
Earth-leakage current breaker
Type
Models provided with harmonic and surge reduction
techniques
General models
Ig1: Leakage current on the electric channel from the earth-leakage current breaker to the input terminals of the servo
amplifier
Page 426 Example of leakage current per km (lg1, lg2) for CV cable run in metal conduit
Ig2: Leakage current on the electric channel from the output terminals of the servo amplifier to the servo motor
Page 426 Example of leakage current per km (lg1, lg2) for CV cable run in metal conduit
Ign: Leakage current when a filter is connected to the input side (4.4 mA per one FR-BIF(-H))
Iga: Leakage current of the servo amplifier
Page 426 Servo amplifier leakage current example (Iga)
Igm: Leakage current of the servo motor
Page 426 Servo motor leakage current example (lgm)
M
Ig2 Igm
Mitsubishi Electric products
NV-SP
NV-SW
NV-CP
NV-CW
NV-HW
BV-C1
NFB
NV-L
K
1
3
11 OPTIONS AND PERIPHERAL EQUIPMENT
11.15 Earth-leakage current breaker
11
425