SCDF Fire Code 2023 Decision Workflows

Clause 5.1 establishes that the installation, control and distribution of wiring of all electrical equipment in buildings shall be in accordance with SS 638 (Code of Practice for Earthing) and SS 551 (Code of Practice for Electrical Installations). This sets the baseline standard for all electrical work in the building, including fire safety systems.

Clause 5.2.1 sets out which fire safety installations require both a primary and a secondary (standby) power supply, and directs the designer to the corresponding Singapore Standard for each system type. It covers fire lifts, fire alarm systems, emergency lighting, emergency voice communication, wet rising mains, sprinkler systems, mechanical ventilation/pressurisation systems, and air supply for generators and fire pumps.

Power supply cables for all equipment required to operate during a fire emergency must be of fire-resistant type complying with SS 299. This applies to all fire safety systems whose secondary power supply is mandated under Clause 5.2.1.

All motors and control equipment for fire safety systems must be suitable for their application and environment. Key requirements include mandatory HRC fuses or MCCBs with magnetic release, automatic resetting no-volt release (so motors restart automatically on power restoration), prohibition on thermal overload trips, and permission of magnetic (short circuit) trips for mechanical ventilation motors serving essential services.

Where emergency generators are provided as secondary power sources, they must comply with SS 535. Outdoor emergency generators have additional fuel containment requirements: the day tank must be double-skin steel construction (or an internal bund retaining 100% of diesel content), and the maximum quantity of diesel in the day tank is 1000 litres.