Emi Of The Drive - Emerson EV2000 Series User Manual

36 Chapter 3 Installation and Wiring
It can prevent the EMI generated by equipment from
entering the power cable, and prevent the EMI
generated by power cable from entering equipment.
Common mistakes in using power cable filter
1. Too long power cable
The filter inside the cabinet should be located near to
the input power source. The length of the power cables
should be as short as possible.
2. The input and output cables of the AC supply filter are
too close
The distance between input and output cables of the
filter should be as far apart as possible, otherwise the
high frequency noise may be coupled between the
cables and bypass the filter. Thus, the filter will become
ineffective.
3. Bad earthing of filter
The filter's enclosure must be earthed properly to the
metal case of the drive. In order to be earthed well,
make use of a special earthing terminal on the filter's
enclosure. If you use one cable to connect the filter to
EV2000 Series Universal Variable Speed Drive User Manual
the case, the earthing is useless for high frequency
interference. When the frequency is high, so is the
impedance of cable, hence there is little bypass effect.
The filter should be mounted on the enclosure of
equipment. Ensure to clear away the insulation paint
between the filter case and the enclosure for good
earthing contact.

3.4.8 EMI of The Drive

The drive's operating theory decides that its EMI is
unavoidable.
The drive is usually installed in a metal cabinet, the
instruments outside the metal cabinet is disturbed by the
drive lightly. The cables are the main EMI source, if you
connect the cables according to the manual, the EMI
can be suppressed effectively.
If you install the drive and other control equipment in
one cabinet, the area rule must be observed. Pay
attention to the isolation between different area, cable
layout and shielding.