Leakage Current Breaker - Mitsubishi Electric MR-J2M-P8B Instruction Manual

12. OPTIONS AND AUXILIARY EQUIPMENT

12.2.7 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 base unit, 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 (11.8 in)) to minimize leakage currents.
Rated sensitivity current 10 {Ig1 Ign Iga K (Ig2 Igm)} [mA] ..........(12.1)
Cable
NV
Ig1: Leakage current on the electric channel from the leakage current breaker to the input terminals
of the base unit (Found from Fig. 12.1.)
Ig2: Leakage current on the electric channel from the output terminals of the drive unit to the
servo motor (Found from Fig. 12.1.)
Ign: Leakage current when a filter is connected to the input side (4.4mA per one FR-BIF)
Iga: Leakage current of the drive unit (Found from Table 12.4.)
Igm: Leakage current of the servo motor (Found from Table 12.3.)
120
100
80
60
40
[mA]
20
0
2 3.5 8 1422 38 80 150
5.5
Cable size[mm
Fig. 12.1 Leakage current example
(Ig1, Ig2) for CV cable run
in metal conduit
Noise
filter
MELSERVO
-J2M
Ig1 Ign Iga
Table 12.3 Servo motor's
Servo motor
output [kW]
0.05 to 0.4
30 60 100
]
2
www.dadehpardazan.ir 88594014-15
Cable
M
Ig2 Igm
leakage current
example (Igm)
Leakage
current [mA]
0.1
12 - 34
K: Constant considering the harmonic contents
Leakage current breaker
Mitsubishi
Type
Models provided with
harmonic and surge
reduction techniques
General models
Table 12.4 Drive unit's
leakage current
example (Iga)
Drive unit Leakage current
capacity [kW] [mA]
0.1 to 0.4 0.3
0.75 0.6
K
products
NV-SP
NV-SW
NV-CP 1
NV-CW
NV-HW
BV-C1
NFB 3
NV-L