Delta CT2000 Series User Manual page 622

TN system
TN: The neutral point of the low voltage transformer or generator is earthed, usually the star point in a three-phase
system. The body of the electrical device is connected to earth via this earth connection at the transformer.
protective earth (PE): The conductor that connects the exposed metallic parts of the consumer.
neutral (N): The conductor that connects to the start point in a 3-phase system or that carries the return current in a
single phase system.
TN-S system
TN-S: PE and N are two separate conductors that are combined together only near the power source (transformer
or generator). It is the same as a three-phase 5-wire system.
Chapter 19 EMC Standard Installation GuideCT2000 Series
19-9
L1
L2
L3
N
PE