Electro-magnetic interference (EMI) and leakage currents
PRECAUTIONS FOR USE OF THE INVERTER
73
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.
• Inverter/converter unit leakage current
400 V class (input power condition: 440 V/60 Hz, power supply unbalance within 3%)
• 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
(When the converter unit is connected, add the
leakage current of converter unit.)
<Example>
• Selection example for the connection of the 400 V class
Item
Breaker designed
for harmonic and
surge suppression
Standard breaker
Leakage current Ig1 (mA)
1
×
66
×
5 m
= 0.11
3
1000 m
Leakage current Ign (mA)
0 (without noise filter)
Leakage current Igi (mA)
1 (without EMC filter)
For the leakage current of the inverter, refer to
the following table.
Leakage current Ig2 (mA)
1
×
66
×
60 m
= 1.32
3
1000 m
Motor leakage current Igm (mA)
0.36
Total leakage current (mA)
2.79
6.15
Rated sensitivity current (mA) (
≥
Ig
×
10) 30
100
Inverter/
converter unit
FR-A800
(Standard model)
FR-A802
(Separated converter type)
Converter unit FR-CC2
H315K, H355K
H400K to H500K
EMC filter
ON
OFF
-
ON
OFF
ON
OFF
35
2
2
35
2
70
2
2
1
1
2
1
2
1
(mA)
Motor capacity (kW)
For " " connection, the amount of leakage current is appox. 1/3 of the above value.
(Three-phase three-wire delta
connection 400 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
Leakage current example of three-
phase induction motor during the
commercial power supply operation
(Totally-enclosed fan-cooled
type motor 400 V 60 Hz)
0
2 0
4 0
6 0
8 0
100
120
Leakage currents (mA)
Leakage currents (mA)
2 3.5
5.5
8 1422
30
38
60
80
100
150
Cable size (mm
2
)
0. 1
0. 2
0. 3
0. 5
0. 7
1. 0
2. 0
1. 5 3. 7
2. 2
7. 5 1522
11
37
30
55
45
5.5
18. 5
Noise
filter
Inverter
ELB
Ig1
Ign
Igi
Ig2
Igm
M
5.5 mm
2
5 m
5.5 mm
2
60 m
400 V
2.2 kW
φ
3
Phase
earthing
(grounding)
Earthed-neutral
system
Summary of Contents for FR-A842-07700
Page 71: ...MEMO 70 ...
Page 91: ...MEMO 90 ...
