Mitsubishi Electric FR-A800, Instruction Manual

Page: 125 / 1042

Precautions for use of the inverter Electro-magnetic interference (EMI) and leakage currents
FR-A800 3 - 3
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
I
Δ
n
≥
10 × (Ig1 + Ign + Igi + Ig2 + Igm)
●
Standard breaker
Rated sensitivity current
I
Δ
n ≥ 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
II002416E, 001044E
Fig. 3-2: Leakage currents
NOTE For star connection, the amount of leakage current is approx. 1/3 of the above value.
1.5 3.7
2.2
7.5 1522
11
37
30
55
45 5.5 18.5
0.1
0.2
0.3
0.5
0.7
1.0
2.0
0
2 0
4 0
6 0
8 0
100
120
2 3.5
5.5
8 14 22
30
38
60
80
100
150
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) Leakage current example
of three-phase induction
motor during the
commercial power
supply operation
(200 V 60 Hz) 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)
Leakage current example
of three-phase induction
motor during the
commercial power
supply operation
(Totally-enclosed fan-
cooled type motor
400 V 60 Hz)
Cable size (mm
2
)
Cable size (mm
2
)
Motor capacity (kW)
Motor capacity (kW)
le
ak
age cu
rr
en
ts (mA)
le
ak
age cu
rr
en
ts (mA)
le
ak
age cu
rr
en
ts (mA)
le
ak
age cu
rr
en
ts (mA)