Emergency Lighting Glossary: 56 Key Terms Explained from A to Z

A–B

Anti-panic lighting (Antipanikbeleuchtung)

Anti-panic lighting is the part of emergency escape lighting that reduces panic in larger areas without defined escape routes and allows occupants to reach an escape route. EN 1838 calls it open area lighting and requires at least 0.5 lx horizontally on the empty core area, excluding a 0.5 m border at the walls. See Anti-panic lighting.

ASR A2.3 and ASR A3.4 (Germany)

ASR A2.3 and ASR A3.4 are German Technical Rules for Workplaces covering escape routes and emergency exits (A2.3) and lighting (A3.4). The content of the former ASR A3.4/3 on safety lighting has been incorporated into ASR A3.4.

Backlit sign (hinterleuchtetes Zeichen)

A backlit sign is a safety sign illuminated from behind or within, as in an exit sign luminaire. With a distance factor of 200 under EN 1838, it can be recognised from twice as far as an externally illuminated sign of the same size.

Battery (Akku)

The battery is the rechargeable energy store of a self-contained emergency luminaire that powers it during a mains failure. Common chemistries are LiFePO4, NiCd and NiMH, which differ in service life, temperature behaviour and environmental impact.

C

Central battery system (Zentralbatterie, CPS)

A central battery system is a central safety power supply without a power limit that feeds all emergency luminaires of a building, or large parts of it, via dedicated circuits. EN 50171 calls it a CPS (Central Power Supply System); it usually needs a separate battery room and fire-resistant wiring.

Centre line (Mittellinie)

The centre line is the imaginary line along the middle of an escape route on which illuminance is assessed. For escape routes up to 2 m wide, EN 1838 requires at least 1 lx on the floor along this line.

Changeover time (Umschaltzeit)

Changeover time is the time between failure of the normal supply and the emergency lighting switching on. It is different from the response time, which states when the required illuminance must be reached.

Circuit integrity (Funktionserhalt)

Circuit integrity is the ability of a cable system to keep working for a defined time during a fire. Wiring from a central or group battery to the luminaires usually needs it – in Germany typically 30 minutes (class E30) under the model wiring guideline MLAR – whereas self-contained luminaires do not.

Colour rendering (Ra)

The colour rendering index Ra is a measure of how naturally colours appear under a light source. EN 1838 requires at least Ra 40 for emergency escape lighting so that safety colours remain recognisable.

D–E

Distance factor (Distanzfaktor)

The distance factor is the number by which the pictogram height of a safety sign is multiplied to obtain its viewing distance. Under EN 1838 it is 200 for backlit and 100 for externally illuminated signs.

Duration test (Betriebsdauertest)

The duration test is the check in which emergency lighting is operated in emergency mode for its full rated duration. EN 50172 requires it at least once a year, with the result recorded in the logbook.

Emergency driver (Notstromtreiber)

An emergency driver is a module with a battery that keeps a standard LED luminaire running during a mains failure, turning it into an emergency luminaire. It is widely used to upgrade existing lighting.

Emergency escape lighting (Sicherheitsbeleuchtung)

Emergency escape lighting is the part of emergency lighting that enables people to leave a building safely or to terminate a dangerous process before leaving. It comprises escape route lighting, anti-panic (open area) lighting and high-risk task area lighting.

Emergency lighting (Notbeleuchtung)

Emergency lighting is the umbrella term for any lighting that operates when the supply to normal lighting fails. It is divided into emergency escape lighting and standby lighting.

Emergency luminaire (Notleuchte)

An emergency luminaire is a luminaire that provides light during a mains failure, powered either by its own battery or by a central safety power supply. It must meet the product standard EN 60598-2-22.

EN 1838

EN 1838 is the European standard for the photometric requirements of emergency lighting. It specifies illuminance levels, uniformity, response times, colour rendering, glare limits and requirements for safety signs.

EN 50171

EN 50171 is the European standard for central safety power supply systems. It distinguishes between low power supply systems (LPS) and central power supply systems (CPS).

EN 50172

EN 50172 is the European standard for emergency escape lighting systems, covering design, installation, documentation and periodic testing. Several countries supplement it nationally, for example Germany with DIN VDE V 0108-100-1.

EN 60598-2-22

EN 60598-2-22 is the product standard for luminaires for emergency lighting. It sets safety and performance requirements, for example for changeover, charging and marking.

EN 62034

EN 62034 is the standard for automatic test systems for battery-powered emergency escape lighting. It describes how self-testing luminaires and test systems carry out function and duration tests and report results.

Escape route (Rettungsweg / Fluchtweg)

An escape route is a route by which people can leave a building in an emergency and reach a place of safety. German law uses Rettungsweg in building regulations and Fluchtweg in workplace law for largely the same concept.

Escape route lighting (Rettungswegbeleuchtung)

Escape route lighting is the part of emergency escape lighting that ensures escape routes and exits can be identified and used safely. For routes up to 2 m wide, EN 1838 requires at least 1 lx on the centre line.

Escape route luminaire (Wegeleuchte)

An escape route luminaire is an emergency luminaire without a pictogram that lights the floor of escape routes or open areas. It is usually operated in non-maintained mode.

Exit sign (Rettungszeichen)

An exit sign is a green safety sign to ISO 7010, such as E001 or E002 "Emergency exit", that shows the way to an exit. Signs must be placed so that at least one is visible from every point on the escape route, see Exit sign viewing distance.

Exit sign luminaire (Rettungszeichenleuchte)

An exit sign luminaire is an emergency luminaire with a backlit safety sign that remains visible during a mains failure. It is frequently operated in maintained mode.

Externally illuminated sign (angestrahltes Zeichen)

An externally illuminated sign is a safety sign lit by a separate luminaire. Under EN 1838 its distance factor is 100, half that of a backlit sign.

F–H

Fire safety strategy (Brandschutzkonzept)

A fire safety strategy is the building-specific document describing how the structural, technical and organisational measures achieve the fire safety objectives. In Germany, the Brandschutzkonzept often specifies where safety lighting is needed, its rated duration and the type of power supply.

Function test (Funktionsprüfung)

The function test is the short, regular check in which a mains failure is simulated to confirm that all luminaires switch to emergency mode. EN 50172 provides for it monthly.

High-risk task area lighting

High-risk task area lighting is the part of emergency escape lighting that allows potentially dangerous processes to be shut down safely. EN 1838 requires at least 10 % of the normal task illuminance, with a minimum of 15 lx, reached within 0.5 seconds.

High-rise building (Hochhaus)

A high-rise building is defined by national building law; in Germany it is a building in which the floor of at least one habitable room lies more than 22 m above ground level. German high-rise rules require safety lighting, including in residential towers.

I–L

Illuminance (Beleuchtungsstärke)

Illuminance is the luminous flux falling on a surface, measured in lux. In emergency lighting it is usually assessed horizontally at floor level, and vertically at safety equipment.

IP rating (IP-Schutzart)

The IP rating is the code under EN 60529 that states how well an enclosure is protected against solid objects and water. IP20 is often sufficient for dry interiors, while damp rooms, car parks or outdoor areas typically call for higher ratings such as IP65.

ISO 7010

ISO 7010 is the international standard for registered safety signs, including the green escape and first aid signs. Older pictograms that do not follow ISO 7010 should be replaced at the next opportunity.

LiFePO4

LiFePO4 (lithium iron phosphate) is a lithium battery chemistry known for high cycle stability, thermal stability and the absence of cadmium. In emergency luminaires it usually tolerates permanent float charging better than older NiCd or NiMH cells.

Logbook (Prüfbuch)

The logbook is the record of all tests, faults and repairs of an emergency lighting installation. EN 50172 requires one, and it may be kept digitally, see Emergency lighting logbook.

Low power supply system (Gruppenbatterie, LPS)

A low power supply system is a central safety power supply with a limited power output that feeds a manageable number of luminaires. EN 50171 calls it an LPS; it sits between self-contained luminaires and a full central battery system.

Luminance (Leuchtdichte)

Luminance is the brightness of a luminous or illuminated surface, measured in candela per square metre (cd/m²). EN 1838 requires at least 2 cd/m² in the green safety colour of an exit sign.

Lux (lx)

Lux is the unit of illuminance; one lux equals one lumen per square metre. Emergency escape lighting works with low values such as 1 lx on escape routes or 0.5 lx in open areas.

M–O

Maintained mode (Dauerschaltung)

Maintained mode is an operating mode in which the emergency luminaire is lit whenever the building is in use and stays lit without interruption during a mains failure. Exit sign luminaires are often run in maintained mode so the sign is always visible.

Maintenance factor (Wartungsfaktor)

The maintenance factor is a design factor that accounts for the decline in light output due to ageing and dirt. It ensures that minimum values are still met at the end of the service life.

NiCd and NiMH batteries

NiCd (nickel-cadmium) and NiMH (nickel-metal hydride) are older battery chemistries found in many existing emergency luminaires. Because of the cadmium, NiCd cells are restricted in the EU, with exemptions having applied to emergency lighting; new luminaires increasingly use lithium chemistries.

Non-maintained mode (Bereitschaftsschaltung)

Non-maintained mode is an operating mode in which the emergency luminaire is off during normal operation and switches on only when the normal supply fails. It is the typical mode for luminaires lighting escape routes and open areas.

Optic (Optik)

The optic is the part of an emergency luminaire that directs the light. Corridor lenses with an elongated distribution suit escape routes, while wide rotationally symmetrical optics suit open areas.

P–R

Photoluminescent sign (langnachleuchtendes Zeichen)

A photoluminescent sign is a safety sign made of material that glows for some time after being charged by light. It does not replace required emergency lighting but may be sufficient where no emergency lighting is required.

Prüfsachverständiger (Germany)

A Prüfsachverständiger is an expert recognised under German building law who inspects safety installations in special buildings at commissioning and at regular intervals. Duties and intervals follow the inspection ordinances of the federal states.

Rated duration (Bemessungsbetriebsdauer)

Rated duration is the time, declared by the manufacturer, for which an emergency luminaire delivers its rated light output in emergency mode. Common values are 1 h, 3 h and 8 h, depending on use and national rules, see Emergency lighting duration.

Response time (Einschaltzeit)

Response time is the time emergency lighting needs after a mains failure to reach the required illuminance. For escape routes, EN 1838 requires 50 % within 5 seconds and 100 % within 60 seconds.

Risk assessment (Gefährdungsbeurteilung)

A risk assessment is the employer's evaluation of workplace hazards required under occupational safety law. In many European countries it is the basis for deciding whether a workplace needs emergency escape lighting.

S–Z

Safety equipment points (Sicherheitseinrichtungen)

Safety equipment points are fire extinguishers, manual call points, first aid points and similar equipment within the meaning of EN 1838. If they are not in an area that is already lit, at least 5 lx vertical illuminance is required at the equipment.

Self-contained system (Einzelbatteriesystem)

A self-contained system is an emergency lighting installation in which every luminaire has its own battery, charger and changeover device. It needs neither a battery room nor fire-resistant wiring, see Self-contained vs central battery.

Self-test (Selbsttest)

A self-test is an automatic check in which an emergency luminaire carries out function and duration tests itself and indicates or reports the result. The basis is EN 62034, see Self-testing emergency lights.

Special building (Sonderbau)

A special building is, in German building law, a building of particular type or use with additional requirements, such as places of assembly, large shops, hotels, high-rise buildings or large car parks. Many of them are explicitly required to have safety lighting.

Standby lighting (Ersatzbeleuchtung)

Standby lighting is the part of emergency lighting that allows normal activities to continue during a mains failure. It is not primarily intended to protect people and is usually an operational choice rather than a legal requirement.

Status LED

The status LED is the indicator on an emergency luminaire that shows operating state, charging state and test results. The meaning of colours and flashing patterns varies between manufacturers.

Uniformity (Gleichmäßigkeit)

Uniformity is the ratio of maximum to minimum illuminance in an area. For escape routes and open areas, EN 1838 limits it to 40:1.

Viewing distance (Erkennungsweite)

Viewing distance is the greatest distance from which a safety sign can still be clearly recognised. It equals pictogram height multiplied by the distance factor.