ABB PQFM Instruction Manual page 46

Figure 27: Identification of the secondary earth point on the PQFM plate
For safety reasons and for proper operation of the filter the main earth point of each
cubicle must be connected to the installation's earth (PE). A copper (Cu) cable of
minimum size 16 mm² is required but local regulations should also be taken into account.
Remark: in PEN systems, the earth connection of the filter must be connected to the
installation's earth (PE) and not to the N-conductor.
Further, the following rules should be respected:
- When the PQFM consists of only one cubicle, the cubicle's main PE-point must be
connected directly to the installation's PE-point.
- When the PQFM consists of more than one cubicle, all cubicles' main PE-points
must be connected directly to the installation's PE-point and additionally, all
cubicles's secondary PE-points must be interconnected. This is illustrated in
Figure 28. The interconnection cable should be minimum 16 mm².
Main earth
connection
point in
cubicles
Secondary
connection
When a factory pre-assembled multi-cubicle is installed, the secondary PE-
interconnections between the different cubicles are already present and the customer
only has to add the main connections of each cubicle to the installation's PE-point.
In other cases, e.g. when integrating different IP00 plates, the customer has to ensure
the proper interconnection of the different cubicles' secondary PE-point. In this, it must
be made sure that the cables are securely fixed and do not run over components.
46 Electrical design and installation ç Manual Power Quality Filter PQFM
Secondary
earth point
(PE)
Master
filter
earth
point
PE
Figure 28: Earth connection guidelines for a multi-unit PQFM
Slave 1 Slave 2
PE PE