Screw Drilled through Aluminum Conductors Creating a Short Circuit

Location: Chilliwack

Regulated industry sector: Electrical – Low voltage electrical system (30V to 750V) 

Incident overview

While installing shelving, a homeowner unknowingly drilled a screw into an unfused ACWU cable in the exterior wall of their duplex townhome. The four-inch screw pierced the rubber outer jacket of the cable, creating a short circuit. The rubber jacket then melted from the heat.

This incident likely would have been prevented if the ACWU cable had been installed with mechanical protection, per the 2021 Canadian Electrical Code rules.