Most imperial system wiring and equipment from the turn of the last century has been replaced, but some very old electrical wiring and equipment is still connected to the grid and in use and is a great danger to the homeowners or occupiers.
Most of this wiring needs to be replaced while some may be suitable for continued operation, in all cases the best and safest option is to contact your preferred electrician and get them to organise an electrical health check for your home.
AS/NZS 3000 (the Wiring Rules) details the safety issues associated with installation wiring. The rules have their origins as far back as 1908 when the Fire Underwriters Associations of NSW, Victoria, Queensland, South Australia and Tasmania adopted the rules of the English Institution of Electrical Engineers in a bid to prevent electrical fires.
Electricity supply was in its infancy in Australia at this time. The first instance was in Tamworth, NSW, late in 1888, and Sydney followed in 1904. One of the main benefits was the replacement of kerosene streetlights, which provided poor lighting and were expensive to operate and maintain.
Split conduit ‘clips all’ fittings manufactured by Gerard Industries were common from the 1920s, giving many years of service and are still operating in many older installations. The conduit was earthed at the switchboard, with the body of the conduit providing the earthing throughout the installation, particularly for lighting circuits. Over the years, the ‘clips all’ fittings may have separated, leaving the conduit unearthed. Short-circuit /overload protection will not operate if cables somehow ‘liven’ up the conduit.
Plumbers working on earthed metallic water pipes have died when touching such conduits. This hazard may also pose a threat with ceiling insulation or when electricians are working in ceilings. Electricians’ Take Five risk- assessment processes should identify suitable control measures when working in ceiling spaces where split conduit exists. The main one should be to isolate all circuits – and the same goes for plumbers.
All of these dangers highlight the importance of hiring a professional contractor to sort out your electrics. NEVER attempt to deal with any electrical circuits or problems yourself, it is very dangerous and in fact illegal.