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(2) Selecting the rated sensitivity current for the ground leakage circuit
breaker
When using the ground leakage circuit breaker with the inverter circuit, select its rated
sensitivity current as follows, independently of the PWM carrier frequency:
Example of leakage current per 1km in
cable path during commercial power
supply operation when the CV cable is
routed in metal conduit
(200V 60Hz)
120
100
80
60
40
20
0
• Breaker for harmonic and surge
Rated sensitivity current: I∆n ≥ 10×(lg1+Ign+lg2+lgm)
• Standard breaker
Rated sensitivity current: I∆n ≥ 10×{lg1+lgn+3×(lg2+lgm)}
lg1, lg2 : Leakage currents of cable path during commercial power supply operation
lgn*
: Leakage current of noise filter on inverter input side
lgm
: Leakage current of motor during commercial power supply operation
* Note the leakage current value of the noise filter installed on the inverter input
side.
2
3.5
8
14
22
80
38
5.5
30
60
100
Cable size (mm
)
2
INSTALLATION AND WIRING
Leakage current example of 3-phase
induction motor during commercial
power supply operation (200V 60Hz)
2.0
1.0
0.7
0.5
0.3
0.2
0.1
150
1.5
Motor capacity (kW)
42
55
3.7
7.5
15 22
37
2.2
5.5
11
18.5
30 45
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