8.1.1 Exit lighting
Rationale - Clause 8.1.1
The exit lighting shall be positioned so that the failure of any single lighting unit will not leave any area in darkness. For essential areas such as exit staircases, internal and external passageways, there shall be no interruption of illumination exceeding 1 sec during the changeover from one energy source to another. This will ensure occupants can see their way down via exit staircase without fear of tripping.
a. Exits of all stations shall be provided with artificial lighting facilities to satisfy the requirements.
b. The minimum illuminance to be provided for all exits and the spacing for luminaires shall be in accordance with the requirements in SS 563.
c. The delay between the failure of the electrical supply to normal lighting and the energization of the exit lighting shall not exceed 1 sec.
8.1.2 Emergency lighting for public areas, corridors, and lobbies
a. Emergency lighting shall be provided in public areas, all corridors, and lobbies
b. The minimum level of illuminance, the spacing of luminaires, and the maximum delay for emergency lighting required in this clause shall be the same as that for the exit lighting.
8.1.3 Emergency lighting for occupied area
a. Emergency lighting shall be provided in the occupied areas following the requirements below:
(1) Along paths leading to corridors, lobbies and exits in all occupied areas where the direct distance from the entry point of the corridor, lobby or exit to the furthest point in the area concerned exceeds 13m; or
(2) Over the whole of such area if there are no explicit paths leading to corridors, lobbies, and exits.
b. Notwithstanding the requirements in Cl.8.1.3a. above, emergency lighting shall be provided in the following locations:
Rationale - Clause 8.1.3b.
The emergency lighting enable the occupants/ maintenance personnel in the mentioned locations to evacuate safely in times of power failure. In addition, the emergency lighting will help firefighters to gain access into any of these rooms or spaces for firefighting or operations purposes.
(1) Lift cars as stipulated in this Code;
(5) Accessible services ducts and cable chambers; and
(6) Areas of refuge within the station.
c. The minimum level of illuminance shall comply with the requirements in SS 563.
d. The delay between the failure of the electrical supply to normal lighting and the energization of the emergency lighting for occupied areas shall not exceed 15 secs.
8.1.4 Emergency lighting for firefighting facilities
Rationale - Clause 8.1.4
The purpose of illuminating these locations is to facilitate the occupants and/ or fire fighters to readily locate fire protection devices and firefighting equipment when normal power supply is interrupted during a fire emergency.
a. Main and sub alarm panels, manual call points, and firefighting equipment shall always be adequately illuminated so that they can be readily located.
b. The minimum level of illuminance shall comply with the requirements in SS 563.
c. The delay between the failure of the electrical supply to normal lighting and the energization of the emergency lighting for firefighting facilities shall not exceed 15 secs.
8.1.5 Secondary source of power supply
a. The delay for energization of the exit and emergency lighting systems between normal supply and the secondary source shall be as stipulated in the relevant clauses.
b. Duration of the secondary source of power supply shall comply with the requirements in SS 563.
c. Location, arrangement and control, installation of electrical wiring of the secondary source of supply, be it in the form of battery, stand by generator, inverter, or other accepted equipment shall comply with the requirements in SS 563.
All exits and emergency luminaires required by the Code shall be of approved type as specified in SS 563.
8.1.7 Exit and directional signs
(1) The entrance to every exit on every floor shall be clearly indicated by an exit sign placed over the exit door. Such signs shall be placed so as to be clearly visible at all times.
(2) Exit sign shall be provided over all exit access doors for rooms with more than one door. See Diagram 8.1.7a.(2).
Exit sign is not required under the following situations:
(a) Room provided with emergency lighting
(i) When a room is provided with only one door. See Diagram 8.1.7a.(3)(a)(i), or
(ii) When a room or internal space is fully open towards an external corridor or the external of a station.
(b) Room without emergency lighting
(i) When a room is provided with only one door and the direct distance from the furthest distance in the room to the exit access door is 7m or less. See Diagram 8.1.7a.(3)(b)(i) – 1 &
(ii) When the furthest point in the room to the exit access door is 13m or less and the wall of the room comprises not less than 50% clear glazing facing (as shown in Diagram 8.1.7a.(3)(b)(ii)):
• an internal corridor covered by emergency lighting, or
• an external corridor, or
• the external of the station.
(iii) When an internal space is fully open towards an external corridor or the external of a station.
(1) In long corridors, in open floor areas, and in all situations where the location of the exits is not readily visible, directional signs shall be provided to serve as guides from all portions of the corridors or floors. See Diagram 8.1.7b.(1).
(2) In rooms where the line of sight to the exit access door is obstructed, directional sign shall be provided.
c. Electrically powered exit and directional signs
The legends, dimensions, design, and installation of the exit signs and directional signs shall comply with SS 563 and SS 508. Either graphic or text format can be used for the design of the signage. Externally illuminated exit signs shall comply with SS 563.
Exception: Externally illuminated exit signs in normally non-occupied plant rooms need not be lighted at all times. However, during power failure, the emergency lighting in the rooms shall provide the required illumination to the signs.
d. Self-illuminating signs
Self-illuminating fire safety signs complying with BS 5499: Part 2 can be used in lieu of emergency signs powered by electricity. The use of self-illuminating exit signs and directional signs powered by radioactive material are permitted in stations provided, the signs comply with UL 924, SS 563, and SS 508 (Part 1, 2, 3, & 5). Either graphic or text format can be used for the design of the signage. In addition, SS 563 Part 1 shall be complied with for determination of the viewing distance with distance factor (Z) fixed at 50.
e. Exit signs in metal enclosures with matt finishes are permitted with openings for venting, testing, and inspection.
f. Under-platform services ducts and cable chamber can use non-illuminated exit signs and directional signs (e.g. sticker type) that are in compliance with SS 508. Non-illuminated exit signs shall also be fixed next to the cat-ladder access.
8.1.8 Photoluminescent marking/ tape
Rationale - Clause 8.1.8
The provision of photoluminescent marking/ tape was introduced to eliminate total darkness scenario where all essential emergency lighting failed during a fire emergency.
a. Photoluminescent marking/ tape to guide occupants along evacuation routes to appropriate exit shall be provided:
(1) along internal walls and/ or floors of the exit staircase, smoke-free lobby, and fire lift lobby;
(2) on the doors of smoke-free lobby, fire lift lobby, and exit staircase; and
(3) along corridor with exit directional signs.
b. The width of photoluminescent marking or tape shall be at least 50mm and be placed at low level. The bottom of the low level sign shall not be less than 150mm or more than 400mm above the floor level.
c. Omission of photoluminescent marking/ tape is permitted on the following conditions:
(1) the emergency power supply of the exit lightings, exit signs, and directional signs in the above locations shall be a self-contained battery pack (single point emergency lighting system) in compliance with SS 563 or central battery supply.
(2) there shall be at least 2 emergency luminaires in the smoke-free lobby, fire lift lobby and corridor with exit directional signs such that no part of such spaces shall be left in total darkness should there be failure of any one of the emergency luminaires.
(3) there shall be at least one emergency luminaire at every exit staircase landing.
Note: Single point (emergency lighting) system – A system of emergency lighting employing self-contained emergency luminaires.