In a non-maintained mode, the emergency lighting remains off during normal operation and only switches on when the general lighting or its power supply fails. This is precisely where the main difference lies during planning: not only a complete power failure, but also a partial failure in the affected area must be reliably detected. This is crucial for escape routes, stairwells, and work areas, ensuring that the relevant section does not remain dark in an emergency. In this context, DIN EN 1838, DIN EN 50172, and VDE 0108-100 are primarily decisive. A central overview of requirements and solutions can be found under Notbeleuchtung.
How the switching works during normal operation and in the event of faults
With emergency lighting featuring a non-maintained circuit, the emergency luminaires are not switched on during daily use.They monitor the normal power supply of the general lighting and switch on automatically as soon as a failure or unacceptable fault is detected. As soon as the regular voltage is stable again, the system switches back automatically and the safety luminaires turn off. For users, this principle is practical, but for planning it is more complex, because the fault detection must match the actually affected area. Suitable emergency lighting are indispensable for illuminating escape routes during a power outage.
Non-maintained operation, maintained operation and combined luminaires
Non-maintained operation
The luminaire is off during normal operation and only becomes active in an emergency. This solution is often used in places where safety lighting only needs to be visible during a power failure and energy consumption during normal operation must remain low.
Continuous operation
In continuous operation, the emergency luminaire remains permanently illuminated or is continuously powered. If the normal mains power fails, the emergency power supply takes over without the luminaire needing to be switched on first. This is typical for exit signs or areas where continuous visibility is required.
Combined emergency luminaires
Combined luminaires integrate general lighting and emergency functions into a single fixture. Depending on the model, one part operates via the normal mains supply and another part via the emergency power supply. Here too, it is essential that the switchover in the event of a failure is safe and compliant with standards.
These requirements are decisive in practice
Automatic activation in the relevant area
Emergency lighting must activate automatically as soon as the general lighting fails. The goal is not simply to have emergency lighting somewhere in the building, but specifically to illuminate the affected area. Therefore, in standby mode, the link between the monitored circuit and the emergency fixture is critically important.
Bridging duration
How long the emergency lighting must remain on depends on the type of building, its use, and the specific requirements of the facility. In practice, durations of 1, 3, or are often required. This operating time is a central criterion when choosing fixtures and batteries, as it directly impacts the battery, system size, and maintenance effort.
Switching time
The switching time describes the interval between a detected fault and sufficient illumination. Longer times are permitted for normal areas than for workplaces with special risks. In practice, a maximum of 15 seconds is often assumed for general areas and a maximum of 0.5 seconds for areas with increased risk. The actual time that must be maintained depends on the use of the area and the applicable requirements.
Why the monitoring of final circuits is so important
The most common misconception regarding emergency lighting with standby switching is overly broad mains monitoring. If only the power supply to a distribution board is monitored, the system will detect a total failure, but not necessarily the failure of a single individual final circuit of the general lighting.Precisely that is critical: if, for example, only the lighting in part of a hallway fails, the evacuation route can remain dark, even though the distribution board as a whole is still energized.
Therefore, emergency lighting must be planned in such a way that even partial failures in the relevant area are detected and reported to the emergency lighting system. In many projects, the general lighting is distributed across multiple circuits for this purpose. This allows the fault to be targeted and detected, and the corresponding emergency lighting in the correct section to switch on. For standby switching, this monitoring of final circuits or areas is often the deciding factor between a formally present and a functionally safe solution.
Individual battery or central battery?
A compact explanation of the two power supply concepts can be found in Einzelbatterie oder Zentralbatterie?.
Self-contained luminaires
With self-contained luminaires, each fixture has its own battery and individual monitoring. If the power supply to the luminaire fails, it automatically switches to battery operation. This makes the solution decentralized and often easy to retrofit.
Central battery systems
In a central battery system, multiple emergency luminaires are powered from a single shared emergency power source. This simplifies maintenance and battery management, but requires a well-designed monitoring concept. Especially in standby mode, the reporting logic must be configured so that not only a total power failure, but also the failure of individual areas reliably triggers activation.
What to consider during selection and planning
The correct operating mode, required bridging duration, switchover time, monitoring concept, and the specific application area of the luminaire are always important. Different requirements may apply to escape routes, open areas, and high-risk workstations. If you are looking for suitable LED emergency lighting, solutions with a self-contained battery or central battery system, MeinLED is happy to assist you with technical product selection and project-oriented advice. The concrete sizing and installation must always be carried out by a qualified electrical engineer.
Frequently asked questions about maintained/non-maintained switching
What regulations apply to emergency lighting?
Essential regulations concern the required lighting function, switchover time, operating duration, monitoring, testing, and the connection to the relevant area.With standby switching, it is particularly important that the failure of general lighting is reliably detected. Depending on the facility, standards such as DIN EN 1838, DIN EN 50172, and VDE 0108-100 are decisive.
How long must the emergency lighting remain illuminated?
This is not the same for every building. Durations of 1, 3, or 8 hours are often prescribed. The specific duration that applies depends on the use, the risk assessment, and the facility-specific requirements. Therefore, the required operating time must be determined early on when selecting the fixture, battery, and system.
What is the difference between emergency lighting and safety lighting?
Emergency lighting is the overarching term. This includes safety lighting, which provides orientation for people during a power failure and allows them to safely evacuate an area.In addition, depending on the application, there are other forms of emergency lighting, such as replacement lighting for the continuation of certain activities. A more in-depth overview can be found in Alles über Notbeleuchtung.
Which DIN standard governs safety lighting?
No single standard covers the subject completely. DIN EN 1838 is central to the lighting requirements. For application, installation concept, and organizational requirements, DIN EN 50172 and VDE 0108-100 are important. Depending on the building type and use, additional regulations may apply.
Does every final circuit need to be monitored in standby mode?
The decisive factor is that a failure in the affected area is reliably detected. Monitoring only the power supply is often not sufficient in standby mode if it leaves partial failures unnoticed.
Whether each final circuit is monitored individually or another standard-compliant area monitoring is used depends on the installation concept and the object.
