Why link is provided in neutral of an AC circuit and fuse in phase of AC circuit?

 What is a Neutral Link?

Neutral links are metallic bars that are usually constructed of copper, aluminum or brass and act as an electrical terminal in an electrical circuit. Below is an image of a neutral link.

 



The neutral link serves as termination point of the neutral of all individual circuits. The Neutral serves circuit return path or path completion line. Current that flows to the load returns trough the neutral, now since the neutral link is a neutral point for various circuits, it is designed to withstand a high amperage.

Back to the question why link is provided in neutral of an AC circuit and fuse in phase of AC circuit?

Suppose there is no neutral link and a fuse is put on the live line and also in the neutral of a single-phase circuit.  

In the event of a phase to neutral fault, very high current would flow in the circuit on both live line and neutral and the fuse would blow. Both wires are fused in so you can't tell for sure which fuse will blow off weather it is the live line fuse or neutral fuse.

In a situation where the neutral fuse blows off every appliance connected to the circuit would go off, Metal halide lamps, Extractor fans etc. and the circuit would appear dead, but the live wire still carries deadly voltage.

This creates a situation that may cause the Electrical Technician to work with the wrong notion that the line has been isolated or and potentially putting the life of the person at risk.

Therefore, a firm properly rated neutral link is provided to ensure that the fuse blows (MCB trips) during over current condition thus leaving the connected load on neutral/ground potential.

Neutral is earthed at the transformer location and thus doesn’t have much potential to harm.

 


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