Chapter G

Sizing and protection of conductors


Breaking of the neutral conductor: Difference between revisions

From Electrical Installation Guide
Home > Sizing and protection of conductors > The neutral conductor > Breaking of the neutral conductor
m (1 revision: no page modification, previous revision = imported ch.G pages cleaned-up)
(Cleanup_2016)
Line 1: Line 1:
{{Menu_Sizing_and_protection_of_conductors}}
{{Menu_Sizing_and_protection_of_conductors}}
<br>


[[File:PictoChap7c.jpg|none]]
[[File:DB422335.svg]]
(see {{FigRef|G64}})<br>The need to break or not the neutral conductor is related to the protection against indirect contact.<br>'''In TN-C scheme'''<br>The neutral conductor must not be open-circuited under any circumstances since it constitutes a PE as well as a neutral conductor.<br>'''In TT, TN-S and IT schemes<sup>(1)</sup>'''<br>In the event of a fault, the circuit-breaker will open all poles, including the neutral pole, i.e. the circuit-breaker is omnipolar.<br>The action can only be achieved with fuses in an indirect way, in which the operation of one or more fuses triggers a mechanical trip-out of all poles of an associated series-connected load-break switch.


(see {{FigRef|G64}})


(1) In some coutries the rules applied for TN-S are the same than the rules for TN-C
The need to break or not the neutral conductor is related to the protection against indirect contact.


== In TN-C scheme ==
The neutral conductor must not be open-circuited under any circumstances since it constitutes a PE as well as a neutral conductor.
== In TT, TN-S and IT schemes{{fn|1}} ==
In the event of a fault, the circuit-breaker will open all poles, including the neutral pole, i.e. the circuit-breaker is omnipolar.
The action can only be achieved with fuses in an indirect way, in which the operation of one or more fuses triggers a mechanical trip-out of all poles of an associated series-connected load-break switch.
{{footnotes}}
<references>
{{fn-detail|1|In some coutries the rules applied for TN-S are the same than the rules for TN-C}}
</references>
[[ru:Отключение нейтрального провода]]
[[ru:Отключение нейтрального провода]]
[[zh:中性线的分断]]
[[zh:中性线的分断]]

Revision as of 00:19, 29 November 2016


DB422335.svg

(see Fig. G64)

The need to break or not the neutral conductor is related to the protection against indirect contact.

In TN-C scheme

The neutral conductor must not be open-circuited under any circumstances since it constitutes a PE as well as a neutral conductor.

In TT, TN-S and IT schemes[1]

In the event of a fault, the circuit-breaker will open all poles, including the neutral pole, i.e. the circuit-breaker is omnipolar.

The action can only be achieved with fuses in an indirect way, in which the operation of one or more fuses triggers a mechanical trip-out of all poles of an associated series-connected load-break switch.

Notes

  1. ^ In some coutries the rules applied for TN-S are the same than the rules for TN-C

ru:Отключение нейтрального провода zh:中性线的分断

Share