Mitsubishi Electric FR-S520E Series Instruction Manual page 24

Main circuit terminals
(3) Selecting the rated sensitivity current for the earth leakage circuit
breaker
When using the earth leakage circuit breaker with the inverter circuit, select its rated
sensitivity current as follows, independently of the PWM carrier frequency:
• Breaker for harmonic and surge
Rated sensitivity current:
Δ ≥
I n 10 × (lg1+Ign+lg2+lgm)
• Standard breaker
Rated sensitivity current:
Δ ≥
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.
<Example>
Leakage current (Ig1) (mA)
Leakage current (Ign) (mA)
Leakage current (Ig2) (mA)
Motor leakage
current (Igm) (mA)
Total leakage current (mA)
Rated sensitivity current
(mA) (≥ Ig × 10)
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
2
2mm ×5m 2mm ×70m
Noise
NV
filter
Inver-
ter
Ig1 Ign
Breaker for Harmonic and
Surge
×
20
×
20
1.66
30
14
2 3.5 8 1422 38 80 150
5.5 3060100
2
Cable size (mm)
2
3
200V
IM
1.5kW
Ig2 Igm
Standard Breaker
5m
1000m
0 (without noise filter)
70m
1000m
0.16
Leakage current
example of three-phase
induction motor
during commercial
power supply
operation
(200V 60Hz)
2.0
1.0
0.7
0.5
0.3
0.2
0.1
1.5 3. 7 7.5 1522 37 55
45
2.2 5.5 18.5 11 30
Motor capacity (kW)
= 0.10
= 1.40
4.78
100