Delta VFD-ED Series, User Manual

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Appendix A. EMC Standard Installation Guide | VFD-ED
A-10
TN-C system
TN-C : PE and N are two separate conductors in an electrical installation similar to a three-phase five-wire system,
but near the power side, PE and N are combined into a PEN conductor similar to a three-phase four-wire system.
L1
L2
L3
PEN
Consumer Earth
Generator or
transformer
TN-C-S system
TN-C-S : A combined earth and neutral system (PEN conductor) is used in certain systems but eventually split up
into two separate conductors PE and N. A typical application of combined PEN conductor is from the substation to
the building but within the building PEN is separated into the PE and N conductors. Direct connection of PE and N
conductors to many earthing points at different locations in the field will reduce the risk of broken neutrals.
Therefore, this application is also known as
protective multiple earthing (PME)
in the UK or as
multiple earthed
neutral (MEN) in
Australia
L1
L2
L3
N
Consumer Earth
Generator or
transformer
PE