Filter
Top Products
35
EMC and leakage currents
3
PRECAUTIONS FOR USE OF THE DRIVE UNIT
(3) Selection of rated sensitivity current of earth (ground) leakage current breaker
When using the earth leakage current breaker with the drive unit circuit, select its rated sensitivity current as follows,
independently of the PWM carrier frequency.
<Example>
Breaker designed for harmonic and surge suppression
Rated sensitivity current:
In10(Ig1+Ign+Igi+Ig2+Igm)
Standard breaker
Rated sensitivity current:
In10{Ig1+Ign+Igi+3(Ig2+Igm)}
Ig1, Ig2: Leakage currents in wire path during commercial power
supply operation
Ign: Leakage current of drive unit input side noise filter
Igm: Leakage current of motor.
Igi: Leakage current of drive unit
Breaker Designed for
Harmonic and Surge
Suppression
Standard Breaker
Leakage current Ig1 (mA)
20
5m
= 0.1
1000m
Leakage current Ign (mA) 0
Leakage current Igi (mA) 1
Leakage current Ig2 (mA)
20
10m
= 0.2
1000m
Motor leakage current Igm (mA) 0
Total leakage current (mA) 1.3 1.7
Rated sensitivity current (mA)
(Ig 10)
15 30
NOTE
Install the earth leakage breaker (ELB) on the input side of the drive unit.
In the connection earthed-neutral system, the sensitivity current is blunt against an earth (ground) fault in the drive
unit output side. Earthing (Grounding) must conform to the requirements of national and local safety regulations and
electrical codes. (NEC section 250, IEC 536 class 1 and other applicable standards)
When the breaker is installed on the output side of the drive unit, it may be unnecessarily operated by harmonics
even if the effective value is less than the rating.
In this case, do not install the breaker since the eddy current and hysteresis loss will increase, leading to temperature
rise.
General products indicate the following models. ...... BV-C1, BC-V, NVB, NV-L, NV-G2N, NV-G3NA, NV-2F earth leakage
relay (except NV-ZHA), NV with AA neutral wire open-phase protection
The other models are designed for harmonic and surge suppression ...... NV-C/NV-S/MN series, NV30-FA, NV50-FA,
BV-C2, earth leakage alarm breaker (NF-Z), NV-ZHA, NV-H
Motor
Leakage current
(mA)
MM-GKR motor 0.1kW to 0.75kW 0
S-PM geared
motor
0.1kW, 0.2kW 0
0.4kW 0.06
0.75kW 0.08
1.5kW 0.13
2.2kW 0.11
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)
Cable size (mm )
2
0
20
40
60
80
100
120
2 3.5
5.5
81422
30
38
60
80
100
150
Leakage currents (mA)
Noise
filter
Drive
unit
ELB
Ig1 Ign
Ig2 Igm
2mm 5m
2
2mm 10m
2
M
3
200V0.75kW
Igi
φ