Central Emergency Lighting VS Self-contained Emergency Lighting

As a part of your lighting design,

you’ll need to choose either a central emergency lighting or self-contained emergency lighting. 

Here we explain their difference and what is the best option for your projects.

Central Emergency Lighting

Central battery systems are normally used for the larger projects. A large multi-storey office block, for example, would require a central battery system to keep the ongoing operational costs at a minimum.

They can be connected directly to the suitably designed mains luminaires, without having to make any modification to the luminaires. And they also operate at full light output under both 'mains healthy' and 'mains failed' conditions making the whole system straight forward.

The control of maintained lights or signs under a central battery system is by sub circuit monitors which will energize the system when main power fails.

Central battery systems offer longer-lasting power solutions. Under temperature-controlled conditions, a central battery can last up to 10 years. Unlike dispersed units that experience temperature fluctuations, central systems maintain consistent conditions, supporting battery longevity.

Central systems are simple to test, simple to maintain, provide completely unobtrusive emergency lighting and offer long-term cost advantages.

When replacement is eventually required, this is usually a quick and simple operation that avoids the disruption caused by having to access and dismantle numerous fittings to change batteries in public areas.

Self-contained Emergency Lighting

Self-contained emergency luminaires provide the simplest and quickest solution as they contain their own batteries and operate independently. They are less time-consuming to install, easy to extend or alter at a later date, and are usually the most cost-effective solution for small-to-medium sized projects.

The cost of installation is relatively cheap as no special cabling is required and they offer greater system integrity as each luminaire is independent of the others, so no special sub-circuit monitoring is required. This also delivers greater system integrity and if any product fails in service the rest of the installation is not affected.

However, each product will require maintenance and regular testing, typically having a functional, short test each month and a full duration test each year. They have a battery life of only 3-5 years, with battery replacement taking approximately one hour per fitting and possible access equipment, this can represent a significant ongoing cost for the building operator. Battery replacement is a simple task, but planning and thought must be given to product location and access to allow these tasks to be undertaken, especially if located at high level.

Self-contained emergency luminaires can also be affected by local environmental conditions. These will of course vary, depending on the system and the location, but the batteries may be affected by especially high or low temperatures. Selecting the correct products will assist in mitigating problems in extreme conditions also selecting whether a product is maintained or non-maintained will assist in keeping the internal batteries within their specified operating temperature range.

What is the best option for your projects?

Advantages of Central Emergency Lighting

1.Good for larger projects

2. Easy to maintain

3. Accessible on-site battery station

4. Self test, automatic fault reporting

5. Longer average battery lifetime about 10 years

6.Almost same lumen performance on both EM and normal mode

Advantages of Self-contained Emergency Lighting

1.Good for small-to-medium sized projects

2.Cheaper and faster to install

3.Free from special sub-circuit monitoring

4.Easily be extended with additional luminaires

5.Each luminaire is independent, and system integrity is improved

Disadvantages of Central Emergency Lighting

1. Daily checks

2. A larger capital equipment cost

3. A central ‘Battery Room’ to house batteries and charging circuits

4. Fixed wiring points make future alterations/ extensions more complicated and costly

5. Higher cost for installation and wiring is due to the requirement for fire-resistant cable to each luminaire

6. May include poor system integrity (failure of the battery or wiring circuit at any point could result in failure in a larger part of the system)

Disadvantages of Self-contained Emergency Lighting

1.Lower battery life of only 3-5 years

2.Batteries will require periodic replacement

3.Potential lower light levels compared with central battery

4.Environmental conditions may vary across a system and the batteries may be affected by higher or lower temperatures

Thus, both self-contained and central power supply systems have their own merits depending on the project. Generally, the decision to use either a central battery or a self-contained system is likely to be cost determined, layout and the size of the buildings. If an installation has longevity low maintenance as a priority then central battery may be the best option. If it is just a case of capital expenditure, and longevity and low maintenance are not significant factors, then self-contained is the best option.

Support

Regarding central battery back-up systems or self-contained emergency luminaires, the final decision on which type of system you choose will largely depend on the priorities for the system. Our Recolux team can advise you on the most suitable system for your project, welcome to contact us for more information.