Earthing Guidelines - ABB PQFM Instruction Manual

The input stage of the active filter is designed in such a way that it shorts the
-
switching frequency ripple current and prevents it flowing into the network. The
(customer provided) input cables are therefore just loaded with the harmonic
currents and therefore they are not fed with high dV/dt. As a consequence, no
special EMC requirements exist for the connection of these cables.
From the above it may be concluded that the connection of an active filter to the network
does not require special cables and special earth connection systems for the protective
earth conductor. Only the harmonic content of the current may ask for a de-rating
current wise, this implying a bigger cross section for a given RMS-current (Cf.
6.6). No special EMC measures are needed. Standard cables types are well suitable for
connecting the active filter to the supply.
6.5

Earthing guidelines

Each PQFM-cubicle two marked earth points (PE). The main earth point is situated at the
top right side of the filter plate
Figure 25: Identification of the main earth point in the PQFM plate (CE version)
Figure 26: Identification of main earth point in the PQFM plate (cULus version)
The secondary earth point is situated at the bottom of the filter main plate
(Figure 25
Main earth
point (PE)
Main earth
point (PE)
Manual Power Quality Filter PQFM ç Electrical design and installation 45
for CE version and Figure 26
Section
for cULus version.)
(Figure 27).