SHENZHEN INVT ELECTRIC CO., LTD. CHV160 Operation Manual
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channel of interference.
Radiated interference is the interference transmitted in electromagnetic wave manner, and
the energy it transmits is inversely proportional to the square of distance.
Electromagnetic interference generation must have three conditions or called-as three
essential elements: interference source, transmission channel and sensitive receiver, any of
which is essential. Solutions for EMC are based on these three. For customers, as the fact the
device is interference source or receiver, the solution for EMC should start at the transmission
channel.
Different electric or electronic devices are manufactured based on different EMC standard
or class, and have different EMC ability.
4.7.2 EMC Features of inverter
Inverters, like other electric or electronic devices installed in a power distribution system, is
a electromagnetic interference source and a electromagnetic receiver as well. The operating
principle of inverter determines that it can produce certain electromagnetic interference noise,
and in order to ensure that it works reliably in certain electromagnetic environment, its design
gives it certain ability of anti-interference. When it is in operation, its EMC features include:
4.7.2.1 Input current is normally nonsinusiodal wave
including plenty of higher
harmonic waves which may produce electromagnetic interference reducing grid power factor
and increasing wire loss.
4.7.2.2 Output voltage is high frequency PMW wave, which can have effect on motor
temperature increase, reducing motor service life and increasing current leakage which make
the leakage protection device malfunction, and in the same time generating strong
electromagnetic interference and having effect on reliability of other electric devices.
4.7.2.3 As an electromagnetic receiver, receiving too strong interference from outside can
make inverter malfunction or even damaged.
4.7.2.4 In system wiring, interference generated by inverter and its anti-interference
supplement each other. The process reducing its interference from outside can increase it
anti-interference ability.
4.7.3 EMC Installation Guide
In order for all electric devices in the same system to work reliably, this section, based on
EMC features of inverter and for site installation reference, introduces its detail installation
process on noise control, site wiring, grounding, leakage current and power supply filter
application. Only these five jobs well done can derive good effective EMC.
4.7.3.1 Noise Control
The wires connected to all control terminals of inverter are shielding wires, which, at cable
entry of inverter, connect the shielding layer to the ground at the nearest point by means of
