HSE HUB › Question of the Day archive › 9 October 2026
ASP practice question: Electrical hazards: overcurrent protection
Question of the Day for Friday, 9 October 2026
ASP · Fire Prevention and Protection
Replacing a 15-ampere fuse with a 30-ampere fuse on a 15-ampere circuit creates what hazard?
Explanation
A 30-amp fuse on wiring rated for 15 amps allows current well above the conductor's safe ampacity before it opens, so the wires can overheat and ignite - defeating overcurrent protection. A larger fuse is not safer, does not reduce current or cool equipment, and fuse rating is directly tied to conductor ampacity. Unprotected conductors overheating is the hazard. (Ref: fuse sizing.)Practise more questions like this
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