Chapter G

Sizing and protection of conductors


Sizing and protection of conductors: Difference between revisions

From Electrical Installation Guide
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=== Conductor sizing and protection ===
=== [[Conductor sizing and protection]] ===


[[Conductor sizing: methodology and definition|Methodology and definition]]  
[[Conductor sizing: methodology and definition|Methodology and definition]]  
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[[Calculation of voltage drop in steady load conditions|Calculation of voltage drop in steady load conditions]]  
[[Calculation of voltage drop in steady load conditions|Calculation of voltage drop in steady load conditions]]  


=== Short-circuit current  ===
=== [[Short-circuit current]] ===


[[Short-circuit current at the secondary terminals of a MV/LV distribution transformer|Short-circuit current at the secondary terminals of a MV/LV distribution transformer]]  
[[Short-circuit current at the secondary terminals of a MV/LV distribution transformer|Short-circuit current at the secondary terminals of a MV/LV distribution transformer]]  
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Short-circuit current supplied by an alternator or an inverter: refer to [[Characteristics of particular sources and loads]]
Short-circuit current supplied by an alternator or an inverter: refer to [[Characteristics of particular sources and loads]]


=== Particular cases of short-circuit current  ===
=== [[Particular cases of short-circuit current]] ===


[[Calculation of minimum levels of short-circuit current|Calculation of minimum levels of short-circuit current]]  
[[Calculation of minimum levels of short-circuit current|Calculation of minimum levels of short-circuit current]]  
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[[Verification of the withstand capabilities of cables under short-circuit conditions|Verification of the withstand capabilities of cables under short-circuit conditions]]<br>
[[Verification of the withstand capabilities of cables under short-circuit conditions|Verification of the withstand capabilities of cables under short-circuit conditions]]<br>


=== Protective earthing conductor  ===
=== [[Protective earthing conductor]] ===


[[Connection and choice for protective earthing conductor|Connection and choice for protective earthing conductor]]  
[[Connection and choice for protective earthing conductor|Connection and choice for protective earthing conductor]]  

Revision as of 08:19, 29 June 2012

Conductor sizing and protection

Methodology and definition

Overcurrent protection principles

Practical values for a protective scheme

Location of protective devices

Conductors in parallel

Practical method for determining the smallest allowable cross-sectional area of circuit conductors

General method for cable sizing

Recommended simplified approach for cable sizing

Busbar trunking systems

Determination of voltage drop

Maximum voltage drop limit

Calculation of voltage drop in steady load conditions

Short-circuit current

Short-circuit current at the secondary terminals of a MV/LV distribution transformer

3-phase short-circuit current (Isc) at any point within a LV installation

Isc at the receiving end of a feeder as a function of the Isc at its sending end

Short-circuit current supplied by an alternator or an inverter: refer to Characteristics of particular sources and loads

Particular cases of short-circuit current

Calculation of minimum levels of short-circuit current

Verification of the withstand capabilities of cables under short-circuit conditions

Protective earthing conductor

Connection and choice for protective earthing conductor

Sizing of protective earthing conductor

Protective conductor between MV/LV transformer and the main general distribution board (MGDB)

Equipotential conductor

The neutral conductor

Sizing the neutral conductor

Protection of the neutral conductor

Breaking of the neutral conductor

Isolation of the neutral conductor

Worked example of cable calculation


Downloads

2010 edition in English: G-Sizing and protection of conductors
2010 edition in French:
G-La protection des circuits 1
G-La protection des circuits 2

External links

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