Rfi Filters - WEG CFW-10 EASYDRIVE User Manual

8.1 RFI FILTER
CFW-10 OPTIONS AND ACCESSORIES
This Chapter describes the optional devices that can be used
internal or external with the CFW-10.
The installation of frequency inverters requires some care in
order to prevent electromagnetic interferences (EMI).
This electromagnetic interference may disturb the operation
of the inverter itself or other devices, such as electronic
sensors, PLCs, transducers, radio equipment, etc. installed
in the proximity.
To avoid these troubles, follow the installation instructions
contained in this Manual.
In this case, avoid the installation of electromagnetic noise
generating circuits, such as power cables, motors, etc. near
to signal or control cables.
Care should also be taken with the radiated interference, by
shielding the cables and the circuits that tend to emit
electromagnetic waves and can cause interference.
The electromagnetic interference can also be transmitted
through power supply line. This type of interference is
minimized in the most cases by capacitive filters which are
already installed inside the CFW-10.
However, when inverters are installed in residential areas, the
installation of additional filter may be required.
These filters may be installed internally (on some types) or
externally.
As defined in standards, the Class B filter has more attenuation
capacity than the Class A filter , thus being more suitable for
residential areas.
The inverters with internal Class A filters have the same external
dimensions as the inverters without filter.
The external Class B filters must be installed between the power
supply line and the inverter input, as shown in Figure 8.1 below.
For installation according to Category I, please, observe the
following:
Instructions for the RFI filter installation:
Install the inverter and the filter on a metallic grounded plate
as near to each other as possible and ensure a good
electrical contact between the grounded plate and the in-
verter and filter frames.
For motor connection use a shielded cable or individual
cables inside a grounded metallic conduit.
CHAPTER 8
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