The Ontario Building Code | Emergency Power Supply

3.2.8.10. Emergency Power Supply

(1) In a building that is more than 18 m in height, measured between grade and the floor level of the top storey, an emergency power supply capable of operating under a full load for at least 2 h shall be provided by an emergency generator or by a separate service not supplied by the same substation as the primary source for fans required for smoke control purposes in Articles 3.2.8.4., 3.2.8.5., 3.2.8.6. and 3.2.8.9.