Faults in any of the following can be identified as a safety hazard:
Earthing:
(or Grounding), to enable a fault current to flow directly to earth.
Earth Leakage Protection:
To prevent an excessive build up of current leaked from electrical appliances into the main wiring system.
Over-Current Protection:
To provide a safe ceiling current load above which a circuit cannot operate.
Wire Sizing:
To prevent too-small wires carrying more than design loads or, alternatively, the need for an excessive over-current protection constraint.
Over-Voltage Protection:
To prevent damage to equipment caused by over-voltages resulting from lightening or switches in the electricity distribution grid.
A variant of this basic checklist was used by the European Copper Institute when it commissioned a survey of domestic electrical systems in Europe. The work was carried out mainly in 2001 as part of the FEEDS programme and the survey provides clear evidence that domestic installations are vastly inferior in quality to the level one may reasonably expect.
In the EU-15 countries, covered only around 40% of installations could be regarded as safe, with 30% showing two or more defects. For the New Member states and the European periphery the situation was much worse, with only 2% or so of installations being »safe« and around 80% showing two or more defects.
DIY extensions … are indicative of makeshift measures to ensure adequate functional use of wiring systems that are not up to the job.
In carrying out its research, the survey focused on the physical evidence that indicated whether or not electrical installations were safe. Inadequate earthing was linked specifically to sockets not being earthed and metal piping not universally being connected to earth. Earth leakage was indicated by the absence of RCDs (Residual Current Devices) and the lack of protection of all areas by an RCD. The lack of over-current protection was indicated by the absence of fuse or circuit breaker protection, the replacement of such devices by higher rated ones or their random tripping. Incorrect wiring size was indicated by sockets and switches getting hot and black burn spots on sockets, switches and panels.
The survey did cover »Protection from Contact«, indicated (in most cases) by the experience of electric shock. It also addressed other »Quality Issues« that indicated deterioration (loose sockets, loose contacts), home made solutions to inadequate systems (extension cords under carpets, DIY system extensions) and the lack of inspection (no inspection for the past ten years). Despite the fact that not all of these issues were surveyed in each country, the survey does give a very good indication of the poor state of Europe’s domestic wiring systems.
By far the most common safety issue observed in the survey was the lack of RCD protection from earth leakage. Earthing, in general, was less of a concern and inadequate over-current protection was shown to be a problem in around 20% of homes across Europe. It appears that low sizing is fairly widespread in Central and Eastern Europe, with around 20% of survey respondents reporting sockets and switches getting hot.
Perhaps the most telling of all indicators of inadequate electrical installation is the regular experience of electric shock. The situation seems to be particularly bad in Central and Eastern Europe, with 10% of respondents giving a positive result in most countries and figures going as high as 26% in Russia.
Europe’s ageing housing stock is one major reason behind its poor standard of electrical installation.
Regarding other quality issues brought out by the survey, the presence or absence of extension cords under carpets and DIY extensions is revealing, as both are indicative of makeshift measures to ensure adequate functional use of wiring systems that are not up to the job. The figures show a very high level of use of extension cords in homes in many countries of Central Europe (50%), with an exceptionally high 82% being recorded in Hungary. DIY additions to the network are also quite common, being apparent in around 20% of homes. Unfortunately, comparable data is not available for EU-15 countries, although France shows a 5% rate of DIY extension.
