Emergency Lighting: Maintained and Non-Maintained Luminaires, Autonomy, and Exit Signs

Short Answer

Emergency lighting is divided into two types: emergency lighting (assists people in safely exiting a building when the normal lighting fails) and reserve lighting (allows work to continue or a hazardous technological process to be completed safely). For emergency tasks, maintained luminaires are used—they remain illuminated during both normal and emergency modes (a typical example is an "Exit" sign above a door). Non-maintained luminaires are also used—they only switch on when the power supply fails. Exit signs along escape routes are typically maintained, whereas general emergency lighting is often provided by non-maintained luminaires or standard luminaires equipped with an emergency power supply (EPS).

Key selection parameters include: autonomy time (1-hour and 3-hour versions are most common), power supply scheme (integrated battery or centralised battery system), IP rating based on the installation environment, and—for exit signs—the pictogram symbol, arrow direction, and recognition distance.

Emergency and Reserve Lighting: What is the difference?

The classification is established by international standards regarding lighting requirements. Emergency lighting is subdivided into emergency lighting and reserve lighting, with emergency lighting further divided into three sub-types.

Emergency Lighting

• Escape route lighting — corridors, stairs, and walkways. The objective is to allow people to see the path and any obstacles upon it.
• Hazardous area emergency lighting — areas where a power failure could cause injury to someone near moving machinery, hot surfaces, or at a height/drop. Significantly higher illuminance levels are required here compared to escape routes.
• Large area lighting (anti-panic) — halls and open spaces where the goal is to prevent panic and guide people towards escape routes.

Reserve Lighting

Emergency lighting is not about evacuation, but about business continuity: control rooms, operating theatres, security posts, and processes that cannot be abandoned instantly. It must provide illumination sufficient to carry out tasks; therefore, standard general lighting luminaires powered by an independent source are typically used, or luminaires equipped with an internal battery pack (emergency battery unit) that provide a significant portion of the rated luminous flux in emergency mode. If emergency lighting is also used for evacuation purposes, it must satisfy the requirements for both types of lighting.

Maintained and Non-Maintained Luminaires

Type	Operation	Application	Considerations
Maintained	The light source operates continuously: from the mains in normal mode, and from a battery or central battery system in emergency mode.	"Exit" signs and directional indicators along escape routes, and areas with high occupancy.	Continuous consumption of LED life and electricity; for exit signs, this is a regulatory requirement rather than an option.
Non-maintained	Switched off in normal mode; automatically switches on when the normal lighting power supply fails.	Evacuation lighting for corridors, stairwells, and production areas; standby/emergency lighting.	Functionality is not visible to the naked eye—a test button or auto-test function and regular inspections are mandatory.
Combined	Some light sources operate continuously, while others operate only in emergency mode.	Combining functional/working lighting and emergency lighting within a single device.	The emergency component must be powered independently from the normal lighting component.

A separate, practical class consists of standard general lighting luminaires with integrated emergency battery packs: manufacturers often denote this in their markings, for example, with an "EM" index (where the digit indicates the hours of autonomy). In normal operation, such a luminaire functions as part of the general lighting; in the event of a failure, it continues to provide light from its own internal battery, typically at a reduced luminous flux. This is highly efficient as it eliminates the need to install a separate range of dedicated emergency luminaires.

Autonomy time and power supply schemes

Self-contained or centralised power supply

• Self-contained (individual battery) — the battery is located inside the luminaire. This is the most common solution: luminaires with decentralised power and individual batteries. Pros: simple installation and independence of each unit; cons: limited battery service life and high maintenance requirements for large installations.
• Centralised power supply — luminaires without internal batteries are powered from a central Uninterruptible Power Supply (UPS) (these are also available, typically operating at 24 V or 230 V DC). Pros: the entire energy capacity and control are centralised, and the battery bank is kept in controlled temperature conditions; cons: requires dedicated supply lines with higher fire resistance requirements (e.g., FE180 / PH90).

Battery type

Comparison: Three emergency lighting configurations

Three typical devices from the catalogue are: a continuous-duty indicator with its own battery, a ceiling luminaire with a non-continuous-duty central battery supply (CBS) providing 3 hours of operation, and a luminaire powered by a centralised 24 V battery system.

Note: for luminaires with centralised power, the autonomy time in the datasheet is listed as zero—this is not an error, as autonomy is determined by the capacity of the central battery rather than the individual device. For the Varton indicator, 1.5 hours is specified from the built-in Li-ion battery, while the ASTZ luminaire with a central battery supply provides 3 hours from a NiCd battery.

Regulatory requirements for emergency lighting

The primary requirements for illuminance levels and operating duration are defined by relevant national building standards; classification and norms for emergency lighting are also specified in international standards. Requirements for the construction of the luminaires themselves are governed by EN/IEC 60598-2-22 (luminaires for emergency lighting). The most common benchmarks required during selection are:

• Along evacuation routes, the horizontal illuminance at the floor level along the centre line of the path must be at least 1 lx.
• For lighting large areas (anti-panic) — at least 0.5 lx on the floor of the zone.
• In high-risk areas, the illuminance is significantly higher — at least 10% of the specified working illuminance, but not less than 15 lx.
• The operating duration of emergency lighting must be at least 1 hour.
• “Exit” light signs are installed above evacuation exits and along evacuation routes such that at least one sign is visible from any point along the path; evacuation signs must comply with safety standards — a white symbol on a green background.

Always verify the exact values for a specific building type and room against the current local building regulations and the design brief: for specific facilities (such as childcare centres, medical institutions, or auditoriums), additional fire safety requirements apply.

Selection of “Exit” pictograms and light signs

Symbol and direction

The most common pictogram types in the catalogue are “Evacuation Route” and “Exit”. There are also text-based signs and symbols, as well as separate “Fire Protection Equipment” signs for indicating fire extinguishers and hydrants. Arrows are available for all directions: down, left, right, straight up, and diagonal (up-right, down-left, etc.). The direction must be chosen based on the actual geometry of the evacuation route, rather than available stock.

Single-sided or double-sided

For signs suspended across a corridor, a double-sided pictogram is required (both types are available in the catalogue), whereas single-sided is sufficient for wall mounting.

Execution/Material

Options include stickers, sheet inserts, plate inserts, acrylic panels, or PVC film. Inserts and panels must only be used with their designated luminaire — always check compatibility by series, as most manufacturers produce pictograms specifically for particular sign models.

Size and recognition distance

The larger the sign, the greater the viewing distance. Pictogram and indicator product cards include a "Recognition Distance" attribute: typical values in the catalogue range from 16 to 60 m, with 30 and 40 m being the most common. Pictogram lengths range from 105 to 600 mm, with standard sizes being 200, 300, and 400 mm. The rule is simple: measure the maximum distance from which a person must be able to see the sign along the evacuation route, and select a pictogram with a recognition distance no less than that value.

If you require a complete "turnkey" solution, select a luminaire that includes the pictogram—this is listed under the "Includes pictogram" attribute in the product card. An example is a compact, continuously operated indicator with a pre-installed "EXIT" pictogram:

IP Rating and Operating Conditions

Main manufacturers in the catalogue: Innolux, FEREKS, LEDEL, and other premium EU brands.

Common Mistakes

1. Non-maintained exit signs. Emergency exit signs must remain visible at all times while the building is occupied, not just during a failure. Non-maintained signs should be replaced with maintained exit signs located above exits and along evacuation routes.
2. Insufficient autonomy. A new battery with a rated one-hour capacity may drop to 30–40 minutes after three years of service. For long evacuation routes or facilities with slow evacuation times, select luminaires with a 3-hour autonomy rating.
3. Ignoring temperature effects. A luminaire with a built-in battery located in an unheated warehouse will fail to meet its rated operating time during winter, and the battery will degrade rapidly. Check the lower limit of the operating temperature range or switch to a centralised power supply system.
4. Incorrect pictograms. A "straight ahead" arrow placed at a corridor turn, a one-way sign mounted across a passage, or a small sign in a long corridor may technically satisfy the requirement of "having a sign," but they fail to actually indicate the path. Select direction, double-sidedness, and recognition distance based on the specific evacuation plan.
5. Lack of testing. A non-maintained luminaire can remain with a dead battery for years without being externally visible. Select models equipped with a test button or automatic testing functionality (check the "monitoring device" attribute in the technical data) and include periodic inspections in your maintenance schedule.
6. Emergency luminaires on the same circuit as normal lighting without phase monitoring. A non-maintained luminaire must activate specifically when the normal lighting for that zone fails. Ensure the monitoring circuit is connected to the same circuit group that it is intended to reserve.