Conductors referenced

Transverse mode noise is noise present across the power wires to a load. The noise is referenced from one power conductor to another including the neutral wire of a circuit. Figure 7.4 depicts common and transverse mode noises. Transverse mode noise is produced due to power system faults or disturbances produced by other loads. Transverse mode noise can also be due to conversion of common mode noise in power equipment or power lines. Some electrical loads are also known to generate their own transverse mode noise due to their operating peculiarities. 

Earthed equipotential bonding and automatic disconnection of supply, known as EEBADS, is the most common technique employed for protection against indirect contact electric shock. Essentially, for earth-referenced supplies, the technique requires the exposed conductive parts of Class I apparatus and equipment to be earthed by means of the protective conductor, with the protective conductor connected back to the main earthing terminal of the installation. 

This Regulation aims to prevent open circuits or high impedances arising in the referenced conductors, which could cause hazardous potential differences between them and the reference point, and to prevent the flow of fault current in systems employing automatic disconnection protection techniques. In most cases, earth is the referencing point for supply systems but there are exceptions, such as motor vehicle wiring systems which are not earthed and which use the chassis as both a reference point and a common return. Other non-earthed systems connect the protective conductor to one of the supply poles. 

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