Mitsubishi Electronics A800 Welding System User Manual


 
Electro-magnetic interference (EMI) and leakage currents
62
PRECAUTIONS FOR USE OF THE INVERTER
NOTE
Install the earth leakage circuit breaker (ELB) on the input side of the converter unit.
In the connection earthed-neutral system, the sensitivity current is blunt against a ground fault in the inverter 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 inverter, it may be unnecessarily operated by harmonics even if the
effective value is within the rating.
In this case, do not install the breaker since the eddy current and hysteresis loss will increase, leading to temperature rise.
The following models are standard breakers BV-C1, BC-V, NVB, NV-L, NV-G2N, NV-G3NA, NV-2F,
earth leakage relay (except NV-ZHA), and 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, and NV-H.
For the leakage current of a 75 kW or higher motor, contact the motor manufacturer.