Emergency Lighting

Emergency Lighting

Emergency lighting is lighting designed to operate when the supply to normal lighting fails. Many fittings contain a rechargeable battery; some buildings use a central battery system. Maintained fittings illuminate during normal use as well as during a supply failure, while non-maintained fittings usually illuminate only when the normal supply fails. Exit signs help identify the way out, but they do not necessarily provide enough light to see steps, changes in level or obstacles along the route. An illuminated sign and emergency escape lighting therefore serve related but different purposes.

For a homeowner in a converted London house or a block of flats, the relevant fittings may be on communal landings rather than inside the home. A private house does not automatically need the same arrangement as a workplace or shared residential building. Shops, offices, workshops and other premises around the M25 need provision suited to their layout, use and fire risk assessment. If you rent or occupy only part of a building, report communal lighting faults to the landlord, managing agent or responsible person rather than assuming another occupier has already raised them.

• —Shared stairs and windowless corridors need particular attention when normal lighting is lost.
• —A working indicator light does not prove that a fitting will illuminate for its required duration.
• —Changes to partitions, doors or escape routes can affect whether existing lighting remains suitable.

Faults you can see, and what may be causing them

Common warning signs include a charging indicator that has gone out, an unfamiliar flashing indicator, a fitting that does not illuminate during a scheduled test, or a light that starts brightly and fades well before the test ends. A maintained exit sign may flicker or remain dark even though nearby lights work. Indicator colours and flash sequences vary between fittings, so a red or green light should not be interpreted without the correct instructions. Make a note of the location and behaviour rather than repeatedly operating a test switch to see whether the problem clears.

Batteries lose capacity with age and can be affected by heat, charging faults or unsuitable replacement parts. Other causes include failed light sources, faulty charging electronics, damaged connections and loss of the permanent supply that keeps a battery charged. A prolonged power cut can leave otherwise serviceable batteries needing to recharge. If several fittings fail together, the cause may be a shared supply or control problem rather than multiple failed batteries. Recent decorating, electrical work or alterations can also disturb fittings or accidentally interrupt their charging supply.

• —Record whether one fitting, one floor or the whole building is affected.
• —Note any recent power cut, building work or change in indicator behaviour.
• —Keep previous test records and fitting instructions available for the electrician.

When a lighting fault becomes an urgent safety problem

A failed fitting can leave a stair edge, doorway or turn in an escape route difficult to see during a power failure. Several failures can make a familiar building confusing, especially for visitors or people with limited mobility. Leaving the problem unresolved also means there may be no dependable backup if normal lighting is lost during an evacuation. The urgency depends on the affected route, available daylight, occupancy and remaining lighting. In a business or shared building, the responsible person should assess whether access or use needs restricting until safe arrangements are in place; a torch is not a substitute for a suitable emergency lighting system.

If there is smoke, burning, sparking or water near electrics, switch off at the main switch only if safe to do so, keep clear and call an emergency electrician. Do not approach a switchboard through water or touch a wet fitting. Call 999 for a fire and leave the building rather than attempting to investigate. For a street-wide power cut, call 105. Emergency lighting batteries have a limited operating duration, so do not assume they will keep an occupied building safely lit throughout an extended outage. Any loss of normal lighting should be managed with the escape routes in mind.

Checks you can make without opening a fitting

From a safe position at floor level, look for visible damage, missing covers, obscured signs and changes in indicator lights. Check whether normal lighting is also affected and whether neighbouring premises have lost power. You can read the building's lighting logbook and the manufacturer's instructions to understand a recorded warning or identify an overdue inspection. Tell the managing agent or responsible person exactly which fitting is affected, using the floor, doorway or existing asset label. Do not climb onto furniture, remove covers, disconnect batteries or touch exposed wiring to investigate.

Routine functional testing should follow the system instructions and the building's agreed testing arrangements, and be undertaken by someone competent to carry it out. Do not turn off random breakers or the main supply merely to test emergency lights. An unplanned test can disrupt other equipment or leave batteries depleted when the building is occupied. A brief functional test establishes whether a light comes on, not whether it can sustain its required duration. If you are unfamiliar with a test key or control panel, leave it alone and arrange an electrician's assessment rather than guessing how it operates.

How an electrician investigates, repairs and verifies the system

The electrician starts by establishing which fittings and escape routes are affected, reviewing available records and checking the system arrangement. With appropriate isolation and electrical safety checks, they can investigate the permanent supply, connections, charging equipment, batteries and light sources. Where a central battery system is involved, diagnosis must account for the shared equipment and connected circuits. Inspection can also reveal whether a fitting has been connected so that ordinary switching interrupts its charging supply. Any work on the electrical installation needs to take account of BS 7671, the IET Wiring Regulations; emergency lighting performance and placement also require their own relevant assessment.

A repair may involve restoring a sound supply connection, replacing a suitable serviceable battery or replacing a failed component where the fitting allows it. A complete replacement may be appropriate when the enclosure is damaged, compatible parts are unavailable or the existing fitting is unsuitable. Replacement selection must consider emergency output, operating mode, required duration and environmental conditions, not just appearance. After work, functional checks and appropriate testing establish operation, with charging time allowed before a meaningful duration test. Results and outstanding defects should be recorded. If the building layout has changed, restoring a failed fitting alone may not resolve gaps in escape-route coverage.

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