Basic design process
Stage1.
Locate luminaires at points of emphasis on escape route:
- At each exit door.
- To illuminate exit and safety signs.
- Near call points.
- Near each staircase.
- Change of direction.
- Near firefighting equipment.
- Change of floor level.
- Near intersection of escape routes.
- Outside final exits.
- Near first aid points.
Stage 2.
For exit signs it is important to check that maximum viewing distances are not exceeded and that if normal lighting is dimmed, eg. Cinemas, the exit signs must be permanently illuminated while the building is occupied (maintained lighting).
Stage 3.
Other areas, which require emergency lighting but are not on escape route.
- Lift car.
- Toilets (above 8m sq floor area)
- Plant rooms.
Stage 4.
Check minimum illuminance levels. After selecting a suitable luminaire check manufacturers spacing tables.
Stage 5.
Anti-panic open areas, this applies to any area over 60m sq floor area, or that have an escape route passing through them.
- Office over 60m sq – Requires lighting.
- Office under 60m sq- Not required.
- Under 60m sq, but part of an escape route – Requires lighting.
Stage 6.
Finally any high risk areas must be considered.
Wiring installation.
The wiring of emergency luminaire should generally be in accordance with normal wiring practice (I.E.E. Wiring Regulations), statutory requirements applicable to the type of building, local by-laws and regulations. The supply for self-contained luminaires should be taken from the un-switched local light source.
Cabling used when installing self-contained emergency luminaires should be of a similar type to that used for the normal main light. In the event of a fire, if the cabling used for the emergency luminaires has greater protection, there may be a chance of the normal lighting failing and the emergency lighting remaining in the normal mode ( ie. Inoperative).Hence it is recommended that self-contained emergency luminaires are wired in PVC insulated cable.
