Frequently Asked Questions

Emergency Lighting

What is the difference between maintained and non-maintained emergency lighting?​

Maintained emergency lights stay lit during normal operation and will remain lit for the rated emergency duration in the event of a mains failure.  Non-maintained emergency lighting is designed to turn on in the event of a mains power failure.

All emergency lighting must be tested monthly. The test is a short functional test in accordance with BS EN 50172 / BS 5266-8. During the test all luminaires and signs should be checked to ensure that they are present, clean and functioning correctly. A test for the full 3 hour emergency duration must be carried out annually with the emergency lighting still being functional at the end of the three hours. The result of both these tests must be recorded and any failures rectified immediately.

Self-test emergency light fittings test themselves automatically to ensure the battery and lamp in each fitting are fully operational. If a problem is detected during the self-test, then a visual warning will be displayed.

An IP rating is a classification to measure the level of protection that electrical equipment has against liquids and solids such as dirt and dust. They are represented by combining the first and second digits. The first digit (1-6) measures the degree of protection against solid projects. The second digit (1-8) measures the degree of protection against water. The higher the number the higher the degree of protection.

If the emergency lighting is functional it will normally display a green LED indicator light on or next to the emergency fitting. This means that the fitting is connected to mains power and the batteries are charging. If the fitting is disconnected from the mains supply the green indicator will turn off and the fitting will light up. Emergency lighting should also be tested monthly.

The battery in emergency light fittings should be changed if it no longer delivers the displayed rated duration. It should also be replaced at the end of life as advised by the manufacturer, which is usually 3 years for NiCD and NiMH.

Toilet facilities with multiple closets that do not have borrowed light and those for use by a disabled person require emergency lighting. If the toilet is only for use by a single person or it is an en-suite facility of a hotel bedroom then emergency lighting is not required.

Self-contained emergency light fittings are generally wired with a 1.5mm² 4-core cable:

  • Switched live
  • Earth
  • Neutral
  • Permanent live

Central battery emergency light fittings require a specialised fire-resistant cable to connect them to the central battery.

A concealed test switch is required for self-contained emergency lighting, to enable the permanent live to be disconnected and allow the internal batteries to power the lighting for the rated duration. The circuit that the test switch is attached to must be separate from the standard lighting, as to not effect any areas of the business or accommodation during use.

Yes, you need to provide illumination to the final point of assembly.

The requirement for emergency lights is established by the fire risks assessment. But the illuminance at floor level of 1 Lux on the escape route and 0.5 Lux in other areas, is deemed acceptable for open-plan offices.

The purpose of illuminating an escape route is to ensure safe evacuation or exit of people from the area and to enable them to locate fire protection and suppression equipment.

Yes, if the emergency light fitting has been installed as a maintained fitting. It will function as a normal light fitting and then switch to emergency operation if there is a mains power failure.

In order to ensure correct visibility, permitting safe evacuation, it is recommended that emergency luminaires are placed at least 2M above floor level. For appropriate luminance, emergency luminaires should be situated within 2M of the exit doors, fire equipment, changes of direction/height and where necessary to highlight potential dangers or safety equipment.

Anti-panic refers to open areas within a building. The purpose of anti-panic illumination of open areas is to reduce the likelihood of panic and to enable the safe movement of people towards escape routes and exits by providing enough visibility to reach a place where the escape route or exit can be located. It is recommended that escape routes or open areas should be illuminated by light falling directly onto the relevant surface. Any obstructions located up to 2 metres above the surface should be illuminated as well. Open area illumination is used in zones with unspecified escape routes including large rooms, halls or buildings with floor area exceeding 60M², or less if a greater number of people gathered there may cause an extra risk.

Yes they do. The purpose of illumination of high risk task areas is to increase the safety of persons involved in potentially dangerous processes or situations and to allow safe and correct completion or interruption of activities in such areas. In high risk task areas, the operating level of illuminance should not be lower than 10% of the normal illuminance required for given activities, however no less than 15 lx.

The pedestrian escape routes from covered and multi-storey car parks should be provided with emergency lighting.

The battery backup of the emergency lighting system will depend on the building and the evacuation strategy. A 3-hour duration is required in entertainment places (cinemas, theatres, etc.) and facilities with a sleeping risk (hotels and guesthouses, etc.). A 3-hour duration is also required if evacuation is not immediate or where early re-occupation may be necessary.

Emergency slave light fittings receive their emergency power supply from a separate central supply of batteries within the premises. The central battery system makes maintenance and testing easier.

Back-Up Power Systems

What is an SLA Battery?

SLA and VRLA are different acronyms for the same battery, Sealed Lead Acid or Valve Regulated Lead Acid. This battery type has the following characteristics: Maintenance-free, leak-proof, position insensitive. Batteries of this kind have a safety vent to release gas in case of excessive internal pressure build up.

A static inverter is designed for use with emergency lighting systems and other safety-related applications, as well as in remote settings such as offshore. It performs a similar role to a standard uninterruptible power supply, but provides backup for a longer time,  either 1 or 3 hours. Inverters provide either a continuous or standby source of AC power from a DC supply, typically a sealed lead-acid battery.

Static inverters must comply with the EN 50171 safety standard for Central Power Supply Systems.

Impedance testing for batteries is a non-intrusive way of preventing battery failure by identifying early signs of weakness or general deterioration in individual cells.

An uninterruptible power supply (UPS) is a device which immediately provides backup power during power failure to keep equipment running for at least a short time when the primary power source is lost. UPS devices also provide protection from power surges. A UPS contains a battery that “kicks in” when the device senses a loss of power from the primary source.

Planning the installation and delivery of a static inverter or UPS system is paramount and should not be overlooked. Some things to consider are:

Will the system fit into the allocated space?

Is the proposed location suitable?

How will the system be transported to the desired location?

The following points are some of the things that should be considered when choosing a suitable location for a static inverter or UPS system:

How much space is available?

Can the floor support the weight of the sytem?

Can access be made secure but also convenient?

What is the impact of the installation on air flow and air conditioning equipment?

Can the chosen location safely accommodate the battery installation?

It is vital to survey the proposed site prior to the delivery of a static inverter. The following questions should be considered:

Is the site easily accessible by road?

Is equipment available to off load the inverter? and does it have a suitable weight capacity?

Are all doorways large enough for the equipment to pass through?

Are there any soft or uneven floors to navigate?

Are there any staris on the route?

Sealed lead acid batteries can be used in any orientation. A sealed battery will not spill acid when tipped on its side, allowing it to be mounted in different positions.

A pure sine wave is a steady, continuous wave that provides a smooth, periodic oscillation. Pure sine wave inverters are at the top of the list of functionality, with the ability to run any and all equipment designed to work on a pure sign wave. All devices you power with a pure sine wave inverter will work to their full specifications.