6. EMC (Electromagnetic compatibility)
EM15 User’s Manual
108
6. EMC (Electromagnetic compatibility)
6.1 Definition
Electromagnetic compatibility is the ability of the electric equipment to run in the electromagnetic interference
environment and implement its function stably without interferences on the electromagnetic environment.
6.2 EMC Standard Description
In accordance with the requirements of the national standard GB/T12668.3, the inverter needs to comply with
electromagnetic interference and anti-electromagnetic interference requirements.
The existing products of our company apply the latest international standard—IEC/EN61800-3: 2004 (Adjustable
speed electrical power drive systems part 3: EMC requirements and specific test methods), which is equivalent to
the national standard GB/T12668.3.
IEC/EN61800-3 assesses the inverter in terms of electromagnetic interference and anti-electronic interference.
Electromagnetic interference mainly tests the radiation interference, conduction interference and harmonics
interference on the inverter (required for the inverter for civil use)Anti-electromagnetic interference mainly tests
the conduction interference rejection, radiation interference rejection, surge interference rejection, fast and
mutable pulse group interference rejection, ESD interference rejection and power low frequency end interference
rejection (specific test items including: 1. Interference rejection tests of input voltage sag, interrupt and change; 2.
Phase conversion interference rejection test; 3. Harmonic input interference rejection test; 4. Input frequency
change test; 5. Input voltage unbalance test; 6. input voltage fluctuation test).
The tests shall be conducted strictly in accordance with the above requirements of IEC/ EN61800-3, and the
products of our company are installed and used according to Section 7.3 and have good electromagnetic
compatibility in general industry environment.
6.3 EMC Guide
6.3.1 Harmonic Effect
Higher harmonics of power supply may damage the inverter. Thus, at some places where mains quality is rather
poor, it is recommended to install AC input reactor.
6.3.2 Electromagnetic Interference and Installation Precautions
There are two kinds of electromagnetic interferences, one is interference of electromagnetic noise in the
surrounding environment on the inverter, and the other is interference of inverter on the surrounding equipment.
Installation precautions:
1)
The earth wires of the frequency inverter and other electric products shall be well grounded;
2)
The power input and output power cables of the inverter and weak current signal cables (e.g. control line) shall
not be arranged in parallel and vertical arrangement is preferable.
3)
It is recommended that the output power cables of the inverter employ shield cables or steel pipe shielded
cables and that the shielding layer be earthed reliably. The lead cables of the equipment suffering interferences
are recommended to employ twisted-pair shielded control cables, and the shielding layer shall be earthed
reliably.
4)
When the length of motor cable is longer than 100 meters, it needs to install output filter or reactor.