A device that de-energizes the circuit when it detects an electrical arc. Circuits that supply bedroom receptacles have been required to be protected by AFCIs since 2002. ESA’s analysis of the Ontario Office of the Fire Marshal’ data concluded that AFCI protection could reduce residential electrical distribution fires by up to 71 per cent. The new OESC expanded the requirements to include most other areas of the home, including outdoors. The new OESC also requires: “combination type” AFCIs that protect wiring within house walls and connected electrical cords against the unwanted effects of arcing.