Main protective bonding

Figure 3.6 Main protective bonding of gas and water supplies.

II) the bath or shower is located in a building with main protective bonding in place, as described in Fig. 3.6 (lET Regulation 411.3.1.2). 

The bathroom is located in a building with a main protective bonding system in place (lET Regulation 701.415.2). Such a system is shown in Fig. 3.6. 

The protection provided by main protective bonding and automatic disconnection of the supply is called ... 

Figure 4.31 Cable sheath earth supplies (TN-S system) showing earthing and main protective bonding arrangements...

Use a sketch to describe the main protective bonding arrangements for the gas, water and electricity supplies in a domestic property. 

C2 meaning an unacceptable condition. The item inspected has been classified as unacceptable. Potential danger is present and the safety of those using the installation may be at risk. For example, the absence of the main protective bonding conductors. 

Test the continuity of the protective conductors including the main protective bonding conductors and supplementary bonding conductors. 

Testing for continuity of protective conductors, including main and supplementary protective bonding (Regulation 612.2.1)... 

The object of the test is to ensure that the CPC is correctly connected, is electrically sound and has a total resistance which is low enough to permit the overcurrent protective device to operate within the disconnection time requirements of Regulation 411.4.6, should an earth fault occur. Every protective conductor must be separately tested from the consumer s main protective earthing terminal to verify that it is electrically soimd and correctly connected, including the protective equipotential bonding conductors and supplementary bonding conductors. 

Use a sketch with notes of explanation to show the earthing and protective bonding arrangements at the mains intake position of a 230V cable sheath supply. 

Rgure 5.14 Cable Sheath Earth Supplies (TN-S System) Showing earthing and main protective equipotential bonding arrangements. 

The whole earth fault current loop examined by this test comprises all the installation protective conductors, the main earthing terminal of the installation and protective bonding conductors, the earthed neutral point and the secondary winding of the supply transformer and the line conductor from the transformer to the point of the fault in the installation. 

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