Breaking of the neutral conductor: Difference between revisions
From Electrical Installation Guide
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{{Menu_Sizing_and_protection_of_conductors}} | {{Menu_Sizing_and_protection_of_conductors}} | ||
[[File:DB422335.png]] | |||
(see {{FigRef|G68}}) | |||
(see {{FigRef| | |||
The need to break or not the neutral conductor is related to the protection against indirect contact (fault protection). | |||
== 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 as the rules for TN-C}} | |||
</references> | |||
Latest revision as of 09:49, 22 June 2022
(see Fig. G68)
The need to break or not the neutral conductor is related to the protection against indirect contact (fault protection).
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
- ^ In some coutries the rules applied for TN-S are the same as the rules for TN-C
