EMERGENCY LIGHTING SYSTEM AND BATTERIES

EMERGENCY LIGHTING SYSTEM AND BATTERIES

EMERGENCY LIGHTING SYSTEM AND BATTERIES

1. WHAT IS A HOUSEHOLD BATTERY, RECHARGEABLE BATTERY AND ACCUMULATOR (OR STORAGE BATTERY)? 

A device that stores electrical energy converted from chemical energy in its body is called a battery. If this conversion is unidirectional, in other words if the battery is thrown away when it is discharged, this is an uncharged battery or a household battery. If the conversion occurs in both directions, it is a rechargeable battery.

Household batteries with the same chemical structure, dimensions and electrical capacities (matching batteries) are assembled individually to create battery groups. While household batteries are used individually in devices such as radios, flashlights and toys, rechargeable batteries are used in handheld drills, cameras, emergency lighting fixtures, etc.

On the other hand, lead-acid-type power-supply sources which are not necessarily ranked within the household and rechargeable batteries category, but which have fully rechargeable properties, are called accumulators or storage batteries. They can be of a sealed type used in emergency lighting fixtures and uninterruptible power supplies, or of flooded type, such as the car batteries.

2. EMERGENCY LIGHTING SYSTEM AND BATTERIES

According to the TS/EN/IEC 60598-2-22 emergency lighting luminaire standard, two types of battery and one type of accumulator (storage battery) can be used in emergency lighting system, these are;

  • High temperature type Nickel cadmium batteries (Ni-Cd)             : Must comply with TS EN/ IEC 61951-1 standard.

  • High temperature type Nickel-metal hydride batteries (Ni-MH)     : Must comply with TS/EN/IEC 61951-2 standard.

  • Sealed-valve regulated type lead-acid accumulators (VRLA)       : Must comply with TS/EN/IEC 60896-21 or TS/EN/IEC 61056-1.

According to the TS/EN/IEC 60598-2-22 emergency luminaire standard, the temperature on the Ni-Cd and Ni-MH battery surface should be at least 5°C and the most 50°C. Conversely, sealed-type lead acid accumulators should not be more than 30°C.

These days, high-temperature type Ni-Cd batteries are used the most in emergency lighting systems, since - in addition to being cheaper- they do not lose their performance even if they are continuously charged with a constant-current. In contrast, Ni-MH batteries are much more environmentally friendly and smaller in size than their Ni-Cd counterparts; however, they are not suitable for continuous constant-current charging. In order to prevent cell damage and assure their longevity, the charging cycle should be in two-stage order or trickle charging method should be applied. Moreover, in products designed with sealed lead-acid batteries, the temperature on the battery surface should not exceed 30 °C. In practice, these batteries can therefore be used at places where the lamps are normally dim, the ambient temperature is low and high-performance is a necessity.

Lithium Ion Li-Ion batteries are not suitable for use in emergency lighting systems, as they are not suitable for continuous charging and in some cases, they heat up and explode. However, lithium-based Lithium Iron Phosphate “Li-FePO4” batteries have been developed in recent years with a 10-year lifespan without fire hazard. As indicated in the emergency lighting luminaire standard, other types of batteries can be used provided that they meet the relevant safety and performance requirements with a certificate. New “Li-FePO4” batteries are expected to fall within the range of standards in due time for their durability and longevity.

According to the EN 60598-2-22 Emergency Lighting Luminaire standard, some restrictions are imposed on the current that the luminaire draws from the accumulator to provide the rated working time even after a few years. Consequently, if the Ni-Cd or Ni-MH battery will be used for one-hour emergency lighting, calculations should be done by assuming its capacity to be 60%; if three hours of emergency lighting is to be done, then 75%. On the other hand, the lead-acid accumulator capacity should be assumed to be 50%. If these calculations are not performed properly by the manufacturers, the emergency lighting luminaire cannot provide the rated running time, after a short while. If batteries that do not meet these requirements are used in the luminaire, due to the performance loss which will occur after a few months, it will be difficult for the fluorescent lamp turn on in case of emergency as well as the lighting time of the luminaire with the power drawn from the battery is reduced dramatically.

In Ni-Cd or Ni-MH batteries, continuous charge current should not exceed 8%, and in accumulators, 40% of the battery capacity.

3. LIFE CYCLES OF DRY-CELL BATTERIES, RECHARGEABLE BATTERIES AND ACCUMULATORS

After a certain period of time, the lives of batteries are consumed when the active substances they contain are depleted or in case of an unwanted chemical or physical change. It is more accurate to describe lives of batteries as cycles rather than using units of time such as months or year. Accordingly, the operation of charging (filling) and subsequent discharging (emptying out) is called a cycle. Disposable, or non-rechargeable batteries, have one life cycle only. However, life cycles may reach 500-1500 cycles in rechargeable type batteries. 

At the end of each cycle, the battery loses some of its nominal energy capacity it had initially and when the capacity drops to 60-70% compared to when it started, the battery life for that device is said to be completed. The concept of number of cycles described above, has taken the condition of battery being fully charged and fully discharged as basis. The life cycle will be much longer if the discharge operations are not carried out in full but performed only partially.

4. THINGS TO CONSIDER WHEN BUYING EMERGENCY LIGHTING LUMINAIRES

When purchasing an emergency lighting luminaire, confirmation must be obtained from the manufacturer, importer or reseller about the following matters:

  • Is there a certificate for the luminaire battery? (Standards are listed in Article 2)

  • Is the Ni-Cd or Ni-MH battery of the luminaire a “High Temperature-type” battery?

5. THINGS TO CONSIDER WHEN INSTALLING A KIT OR BATTERY TO THE LUMINAIRE

  • Electrical equipment must only be installed by authorized persons.

  • Installers and workplaces should take necessary job safety measures. Metal objects such as rings, pendants etc. should be removed before the installation.

  • If the luminaire has a metal body, it must definitely be grounded.

  • The cable between the kit and the battery must not be extended by cutting; otherwise the lamp may not work properly, because when the lamp is activated and lit, enough voltage will not be transmitted to the electronic circuit due to the drop in the voltage. Filament darkening or failure may be experienced on fluorescent lamps.

  • Inside the luminaire, the battery and the kit should be installed in the farthest place from the heat sources such as the light bulb or the ballast. 

  • According to EN 60598-2-22 Emergency Lighting Luminaire standard, the temperature on the surface of the battery should be between 5-50⁰C.

  • Connection cables should be kept as short as possible. Electronic ballast manufacturers require to keep the cable connections to some pins short. Care should be taken to keep these pins short when connecting.

  • Tests with a luminaire that comes with a kit must be carried out with either a full battery or a power source that shows the same characteristics as the battery.

  • The positive and negative terminals of the batteries must not be shorted in any way, otherwise work accidents may occur.

  • Serial and parallel connections of batteries should not be done randomly, and should be asked to the manufacturer or left for the specialists.

6. THINGS TO CONSIDER WHEN INSTALLING THE LUMINAIRE TO ITS PLACE

  • Electrical equipment must only be installed by authorized persons.

  • Installers and workplaces should take necessary job safety measures.

  • Metal objects such as rings, pendants etc. should be removed before the installation.

  • After the first installation, the battery must be operated continuously for at least 48 hours to fully charge. If necessary, the luminaire should be subjected to 3-5 times 48 hours charge/discharge cycle to ensure full performance of the batteries.

  • If any test is to be performed, make sure that the batteries are charged for at least 48 hours.

  • In the case of site type applications that will be in service at a later date, the lifetime and capacities of both the lamps and the batteries are severely reduced due to frequent power outages. In such applications, when installing the luminaires, the battery socket must be removed and must be reinserted shortly before the building is put into function.

  • Once a month, the supply voltage of the kit should be cut for 1-2 minutes from the fuse to which it is connected and tested to see if functioning properly. (Function Test)

  • Once a year, the unit must be disconnected from the supply voltage to which it is connected, and its operation and activation time during an emergency should be tested. (Duration Test)

  • If the kit does not operate for the time specified in an emergency, its battery must be replaced with a new one. 

7. THINGS TO CONSIDER WHEN DISPOSING BATTERIES

  • Batteries should not be heated in any way, thrown into fire or kept in places with direct sunlight.

  • Batteries should not be dismantled, opened, punctured or crushed.

  • Batteries should not come into contact with water or other oxidizing gases and liquids.

  • Waste batteries should be disposed of in the waste battery collection boxes or sent to the place of purchase. They should never be incinerated, buried to the ground, thrown in seas, rivers, lakes or sewers.

8. EEC ELECTRONICS BRAND BATTERIES

EEC Electronics brand batteries manufactured in accordance with EN/IEC standards are high-quality, safe, and long-lasting. They are high temperature type batteries. It performs smoothly between -5 and +55°C. There is a plug-in type plug that offers reverse installation protection. EEC Electronics brand batteries are under EEC Electronics guarantee.


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