Mitsubishi Electric FR-A820-00046 Instruction Manual Page 125

Precautions for use of the inverter
Selecting the rated sensitivity current for the earth leakage circuit breaker
When using an earth leakage circuit breaker with the inverter circuit, select its rated sensitivity current
as follows, independently of the PWM carrier frequency.
● Breaker designed for harmonic and surge suppression
Rated sensitivity current
IΔn ≥ 10 × (Ig1 + Ign + Igi + Ig2 + Igm)
● Standard breaker
Rated sensitivity current
IΔn ≥ 10 × {Ig1 + Ign + Igi + 3 × (Ig2 + Igm)}
Ig1, Ig2: Leakage currents in wire path during commercial power supply operation
Ign: Leakage current of inverter input side noise filter
Igm: Leakage current of motor during commercial power supply operation
Igi: Leakage current of inverter unit
Example of leakage
current of cable path per
1 km during the
commercial power
supply operation when
the CV cable is routed in
metal conduit
(200 V 60 Hz)
Cable size (mm
Fig. 3-2:
NOTE
For star connection, the amount of leakage current is approx. 1/3 of the above value.
FR-A800
Leakage current example
of three-phase induction
motor during the
commercial power
supply operation
(200 V 60 Hz)
2.0
120
100
1.0
8 0
0.7
0.5
6 0
0.3
4 0
0.2
2 0
0
0.1
1.5 3.7
2 3.5
8 14 22
38
80
150
2.2
5.5
30
60
100
2
)
Motor capacity (kW)
Leakage currents
Electro-magnetic interference (EMI) and leakage currents
Example of leakage
current per 1 km during
the commercial power
supply operation when
the CV cable is routed in
metal conduit
(Three-phase three-wire
delta connection
400 V 60 Hz)
7.5 1522
37
55
5.5
1 1
18.5
30
45
Cable size (mm
Leakage current example
of three-phase induction
motor during the
commercial power
supply operation
(Totally-enclosed fan-
cooled type motor
400 V 60 Hz)
2
)
Motor capacity (kW)
II002416E, 001044E
3 - 3