Delta Electronics VFD037CH23A-21 — обзор систем TN: TN-S и TN-C в электрических установках [629/638]

Превью страниц Страница 629 / 638

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.

TN-C system

TN-C: PE and N are two separate conductors in an electrical installation similar to a three-phase 5wire

system, but near the power side, PE and N are combined into a PEN conductor similar to a three-phase 4

wire system.