[ Right connections ]
Shocking work
In this regular section we look at cases of poor-quality workmanship, mistakes in installation and shoddy practices. This issue, John Rothwell from ELECSA provides an insight on what can go wrong – and how best to avoid it
Burning issues... poor installation practice was the most likely cause of the fi re.
been installed in the ceiling, which had been destroyed, and were installed in an adjacent area of the ceiling, which had not been destroyed.
The outcome:
The result was considerable fi re damage to the property. However, the result could have been more catastrophic had the work been fully completed and had the premises been inhabited. In this instance, the consequences could have been life-threatening and loss of life could not be have been ruled out.
Case study 1
The installation:
The electrical installation was a complete rewire of a large, two-storey, semi-detached domestic property. The electrical installation was in various stages of completion, being in part second fi x, and in fact several lighting circuits’ ring fi nal circuits were said to have been energised to provide ‘temporary lighting and power’ during the construction stage, but this was de-energised before our inspection.
About the author
John Rothwell
John Rothwell IEngMIET is a senior inspector in ELECSA’s inspections team and has been working in the electrical industry for 42 years.
What went wrong:
A fi re caused substantial damage to the support timbers and ceiling in part of the roof space. Our inspection was commissioned at the request of an interested party who wanted to have an authoratative opinion on what was the likely cause. Although it was not certain, in the absence of evidence
to suggest otherwise, it was likely that the installed mains voltage GU10 downlights were the cause. These had
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ECA Today Summer 2010
What should have been done?
It was discovered that a considerable number of the GU10 downlights that were installed in the locations that were not subject to fi re damage had, in fact, been positioned adjacent to – and in some instances touching – fl ammable building support timbers. The manufacturer’s instructions for the type of fi ttings installed stipulates that the area of free space surrounding the fi tting must be not less than 50mm, and furthermore BS7671:2008 17th Edition Wiring Regulations number 134.1.1 requires electrical equipment to be installed in accordance with manufacturers’ instructions. The manufacturer’s instructions in this case state:
‘Ensure that there is adequate free air circulation of at least 50mm around the luminaire. All luminaires run hot. It is the installer’s responsibility to consider fi re risk and take appropriate precautions. ‘The luminaires must not under any circumstances be
covered with any insulation material and luminaires must not be installed close to fl ammable materials.’ Therefore, it is not unreasonable to deduce that the
heat at the hot surface of the downlights could not be effectively dissipated and that this was the likely cause of the fi re. Inadequate heat dissipation from this type of lighting
has caused similar situations in other installations and it is, therefore, of the utmost importance that the manufacturer’s instructions for installation are followed so the build-up of heat does not become problematic. In addition, poor installation practice was evident at the termination of the fi xed wiring cables to the downlighters, namely: 1) Bare cores were exposed outside the enclosure where the cable sheath had been stripped excessively;
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