LV switchgear: functions and selection: Difference between revisions
From Electrical Installation Guide
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== [[General|General]] == | == [[General|General]] == | ||
==== Methodology and definition ==== | ==== Methodology and definition ==== | ||
==== Overcurrent protection principles ==== | ==== Overcurrent protection principles ==== | ||
==== Practical values for a protective scheme ==== | ==== Practical values for a protective scheme ==== | ||
==== Location of protective devices ==== | ==== Location of protective devices ==== | ||
==== Conductors in parallel ==== | ==== Conductors in parallel ==== | ||
== [[Practical method for determining the smallest allowable cross-sectional area of circuit conductors|Practical method for determining the smallest allowable cross-sectional area of circuit conductors]] == | == [[Practical method for determining the smallest allowable cross-sectional area of circuit conductors|Practical method for determining the smallest allowable cross-sectional area of circuit conductors]] == | ||
==== General ==== | ==== General ==== | ||
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==== General method for cables ==== | ==== General method for cables ==== | ||
==== Recommended simplified approach for cables ==== | ==== Recommended simplified approach for cables ==== | ||
==== Busbar trunking systems ==== | ==== Busbar trunking systems ==== | ||
== [[Determination of voltage drop |Determination of voltage drop]] == | == [[Determination of voltage drop|Determination of voltage drop]] == | ||
==== Maximum voltage drop limit ==== | ==== Maximum voltage drop limit ==== | ||
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==== 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|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 ==== | ||
==== 3-phase short-circuit current (Isc) at any point within a LV installation ==== | ==== 3-phase short-circuit current (Isc) at any point within a LV installation ==== | ||
==== Isc at the receiving end of a feeder in terms of the Isc at its sending end ==== | ==== Isc at the receiving end of a feeder in terms of the Isc at its sending end ==== | ||
==== Short-circuit current supplied by an alternator or an inverter ==== | ==== Short-circuit current supplied by an alternator or an inverter ==== | ||
== [[Particular cases of short-circuit current |Particular cases of short-circuit current]] == | == [[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 ==== | ||
==== Verification of the withstand capabilities of cables under short-circuit conditions ==== | ==== Verification of the withstand capabilities of cables under short-circuit conditions ==== | ||
== [[Protective earthing conductor |Protective earthing conductor]] == | == [[Protective earthing conductor|Protective earthing conductor]] == | ||
==== Connection and choice ==== | ==== Connection and choice ==== | ||
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==== Conductor sizing ==== | ==== Conductor sizing ==== | ||
==== Protective conductor between MV/LV transformer and the main general distribution board (MGDB) ==== | ==== Protective conductor between MV/LV transformer and the main general distribution board (MGDB) ==== | ||
==== Equipotential conductor ==== | ==== Equipotential conductor ==== | ||
== [[The neutral conductor |The neutral conductor]] == | == [[The neutral conductor|The neutral conductor]] == | ||
==== Sizing the neutral conductor ==== | ==== Sizing the neutral conductor ==== | ||
==== Protection of the neutral conductor ==== | ==== Protection of the neutral conductor ==== | ||
==== Breaking of the neutral conductor ==== | ==== Breaking of the neutral conductor ==== | ||
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==== Isolation of the neutral conductor ==== | ==== Isolation of the neutral conductor ==== | ||
== [[Worked example of cable calculation |Worked example of cable calculation ]]<br> == | == [[Worked example of cable calculation|Worked example of cable calculation ]]<br> == | ||
Revision as of 08:49, 22 January 2010
