Mains extension melted – not fully paid out
- Safety Flash
- Published on 12 July 2021
- Generated on 18 September 2025
- IMCA SF 19/21
- 1 minute read
An under-rated transformer was installed, causing overheating and thermal degradation of the transformer which subsequently tripped the breaker and activated the vessel’s fire alarm.
A mains extension cable melted during use. This occurred during cutting on deck on a vessel in dry dock; sub-contractors did not fully pay out an extension cable reel they were using to power their equipment. As a result there was induction heating and a melting of cable cord.
Additionally, it was noted that the extension cable was damaged and fixed by tape in places.
extension cable was fixed by tape in places
What went wrong?
The sub-contractor personnel were unaware of the dangers of induction coil heating on mains extensions not fully unwound.
The extension cable and reel had not been inspected by a qualified person before use, and given the fact that it had a taped repair, should never have been used at all.
Actions
- Thorough inspection of mains electrical cabling before use.
- Fully pay out coiled mains extension cables before use.
- Consider the use of specialist 110v electrical equipment.
Please review IMCA “Be prepared to work safely” video on Electrical hazards.
Related Safety Flashes
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IMCA SF 10/21
8 April 2021
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IMCA SF 19/19
12 August 2019
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IMCA SF 10/13
25 June 2013
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