Leakage Current Breaker - Mitsubishi Electric Melservo-J3 Series MR-J3-B Instruction Manual

11. OPTIONS AND AUXILIARY EQUIPMENT

11.18 Leakage current breaker

(1) 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 a leakage current breaker according to the following formula, and ground the servo amplifier, servo
motor, etc. securely.
Make the input and output cables as short as possible, and also make the grounding cable as long as
possible (about 30cm) to minimize leakage currents.
Rated sensitivity current 10 {Ig1 Ign Iga K (Ig2 Igm)} [mA]
Cable
NV
Ig1: Leakage current on the electric channel from the leakage current breaker to the input terminals of the
servo amplifier (Found from Fig. 11.3.)
Ig2: Leakage current on the electric channel from the output terminals of the servo amplifier to the
servo motor (Found from Fig. 11.3.)
Ign: Leakage current when a filter is connected to the input side (4.4mA per one FR-BIF(-H))
Iga: Leakage current of the servo amplifier (Found from Table 11.5.)
Igm: Leakage current of the servo motor (Found from Table 11.4.)
120
100
80
60
40
[mA]
20
0
Fig. 11.3 Leakage current example (lg1, lg2) for CV cable run in metal conduit
Noise
filter
Servo
amplifier
Ig1 Ign Iga
2 3.5 8 1422 38 80 150
5.5 30 60 100
Cable size[mm ]
2
a. 200V class
Cable
M
Ig2 Igm
[mA]
11 - 82
(11.1)
K: Constant considering the harmonic contents
Leakage current breaker
Mitsubishi
Type
Models provided with
harmonic and surge
reduction techniques
General models
120
100
80
60
40
20
0
2 5.5 14
3.5 8 22
30
Cable size[mm
b. 400V class
K
products
NV-SP
NV-SW
NV-CP 1
NV-CW
NV-L
BV-C1
3
NFB
NV-L
38 100
60 150
80
]
2