Fundamental requirements for safety – (IEE Regs Part and Chapter ) – The Health and Safety at Work Act – The Electricity at Work Regulations – Earthing – Definitions used in this chapter – Earth: what it is, and why and how we connect to it – Earth electrode resistance – Earthing in the IEE Regulations – Earthing systems – Earth fault loop impedance – Determining the value of total loop impedance – Residual current devices – Supplementary bonding – Problems – Protection – Definitions used in this chapter – What is protection? – IP codes – Protection against electric shock – Protection against direct contact – Protection against indirect contact – Exemptions – Protection against direct and indirect contact – Reduced low voltage systems – Protection against overcurrent – Breaking capacity of fuses and circuit breakers – Fuse and circuit breaker operation – Discrimination – Position of protective devices – Protection against overvoltage – Protection against undervoltage – Precautions where there is a particular risk of fire – Control – Isolation and switching – Circuit design – Design procedure – Voltage drop – Shock risk – Thermal constraints – Assessment of general characteristics .
