Mitsubishi Electric FR-F700PJ Series Manual page 69

Selection of rated sensitivity current of earth leakage circuit breaker
When using the earth leakage current 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n 10  (Ig1 + Ign + Igi + Ig2 + Igm)

Standard breaker
Rated sensitivity current:
I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
Example of leakage current of
cable path per 1km during the
commercial power supply operation
when the CV cable is routed in
metal conduit
(200V 60Hz)
120
100
8 0
6 0
4 0
2 0
0
2 3.5 8 1422 38 80 150
5.5 30 60 100
Cable size (mm )
2
Example of leakage current per 1km during
the commercial power supply operation
when the CV cable is routed in metal conduit
(Three-phase three-wire delta
connection 400V60Hz)
120
100
8 0
6 0
4 0
2 0
0
2 3.5 8 1422 38 80 150
5.5 30 60 100
Cable size (mm 2 )
For " " connection, the amount of leakage current is appox.1/3 of the above value.
Leakage current example of
three-phase induction motor
during the commercial
power supply operation
(200V 60Hz)
1.0
0.7
0.5
0.3
0.2
0.1
0.07
0.05
0.03
0.02
20
0.1 0.2 0.75 2.2 5.5 11
0.4 1.5 3.7 7.5 15
Motor capacity (kW)
Leakage current example of
three-phase induction motor during the
commercial power supply operation
(Totally-enclosed fan-cooled
type motor 400V60Hz)
2. 0
1. 0
0. 7
0. 5
0. 3
0. 2
0. 1
1.5 3.7 7.5 15
2.2 5.5 11 20
Motor capacity (kW)
Example
2 2
5.5mm 5m 5.5mm
Noise
ELB
filter
Inverter
Ig1 Ign Ig2
Igi
(Note) 1. Install the earth leakage circuit breaker (ELB) on the
input side of the inverter.
2. In the connection earthed-neutral system, the
sensitivity current is blunt against an earth
(ground) fault in the inverter output side.
Earthing (Grounding) must conform to the
requirements of
regulations and electrical codes. (NEC section
250, IEC 536 class 1 and other applicable
standards)
 Selection example (in the case of the left figure (400V
class connection))
Breaker Designed for
Harmonic and Surge
Suppression
1
Leakage current Ig1
 66 
(mA)
3
Leakage current Ign
0 (Without a noise filter or Filterpack)
(mA)
Leakage current Igi
(mA)
1
Leakage current Ig2
 66 
(mA)
3
Motor leakage
current Igm (mA)
Total leakage
2.79
current (mA)
Rated sensitivity
current (mA) 30
(Ig 10)
60m
3φ
M
400V
2.2kW
Igm
national and local safety
Standard Breaker
5m
= 0.11
1000m
1
60m
= 1.32
1000m
0.36
6.15
100
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