Selection Of Rated Sensitivity Current Of Earth Leakage Breaker - Mitsubishi Electric FR-F700 Manual

Selection of rated sensitivity current of
earth (ground) leakage 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 designed for harmonic and surge suppression
Rated sensitivity currentI ∆n ≥ 10 × (Ig1 + Ign + Igi + Ig2 + Igm)
⋅
Standard breaker
Rated sensitivity currentI ∆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 : Inverter unit leakage current
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
Power supply size (mm
For " " connection, the amount of leakage current is 1/3
example
2 × 5m 2 × 60m
5.5mm 5.5mm
ELB
Noise
filter
Inverter
Ig1 Ign Ig2
Igi
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 1522 37 55
2. 2 5.5 11 18. 5 30 45
)
2 Motor capacity (kW)
3φ
IM
400V
2.2kW
Igm
(Note)1. Install the earth leakage breaker (ELB) on the input side
of the inverter.
2. In the connection earthed-neutral system, the
sensitivity current is purified against an earth (ground)
fault in the inverter output side. Earthing (Grounding)
must conform to the requirements of national and local
safety regulations and electrical codes. (JIS, NEC
section 250, IEC 536 class 1 and other applicable
standards)
Selection example (in the case of the left figure)
Breaker Designed for
Harmonic and Surge
Suppression
1
Leakage current
Ig1 (mA)
3
Leakage current
Ign (mA)
Leakage current Igi
Refer to the following table for the leakage current of the
(mA)
1
Leakage current
Ig2(mA)
3
Motor leakage
current Igm (mA)
Total leakage
current (mA)
Rated sensitivity
current (mA)(≥ Ig ×
10)
Inverter leakage current (with and without EMC filter)
Input power conditions
(200V class : 220V/60Hz, 400V class : 440V/60Hz,
power supply unbalance within 3%)
Voltage
(V)
200
Phase
grounding
400
Earthed-neutral
system
400
* For the 200V class 0.75K and 1.5K, the EMC filter is always valid.
The leakage current is 1mA.
Standard Breaker
5m
× 66 × = 0.11
1000m
0 (without noise filter)
1 (Without EMC filter)
inverter
60m
× 66 × = 1.32
1000m
0.36
2.79 6.15
30 100
EMC Filter
ON (mA) OFF (mA)
22(1) * 1
30 1
1 1
58