Converting standard luminaires for emergency use is common practice in the UK, but getting it wrong can have serious implications for installers and specifiers as well as converters.
In most of Europe, centralised lighting systems with dedicated emergency luminaires are very much the order of the day. In the UK, however, converted emergency luminaires are very popular because they offer a number of design benefits. On the downside, they also present potential problems if the conversion is not carried out properly. Unfortunately, the desire to cut costs, combined with loose specifications, often leads to shoddy conversions that ignore the complexity of the modern luminaire.

Prevention of problems
To counter these problems, the Industry Committee for Emergency Lighting (ICEL) was produced a certification scheme. This scheme ensures that compliant luminaires have been converted in line with best practice and have been thoroughly tested after conversion. ICEL 1004 was published some time ago, but the ongoing problem of 'dodgy' conversions has prompted ICEL to modify it to provide greater clarity.

"We have updated the document to assist the readers to better understand their legal obligations and the surest route to compliance for the life-saving products they are producing," explains Bernard Pratley of ICEL and the Lighting Industry Federation (LIF). "It has been necessary to revisit the subject because of the large number of poor quality re-engineered luminaires – conversions of mains lighting luminaires for emergency lighting use – that are appearing on sites.

"The members of ICEL and their colleagues in the LIF are fully supportive of this document and are observing the procedures laid out within it. It is now up to the rest of the industry (contractors and conversion houses) to catch up with ICEL and the LIF and put quality, life-saving emergency luminaires in the office and other premises where the occupants deserve the best," he continues.

In this respect it is vital that emergency lighting products are not treated as just another light fitting. They play a vital role in ensuring the safety of a building's occupants in the event of mains failure, fire or other emergency and need to be given the same priority as other life-saving measures. Conversions carried out to the specification of ICEL 1004 will ensure they retain those qualities, but poor conversions may suffer in terms of safety and performance.

Making a conversion
At the very least, poor or unreliable performance will lead to callbacks for the contractor. At worst, following an incident where injury or death occurs because the emergency lighting failed, the specifier or installer could find themselves in court.

In most cases, the contractor will leave the conversion to the manufacturer or a third party converter but there is still a responsibility to ensure that the conversion has been carried out properly. Of the hundreds of conversion shops in the UK, only a handful have signed up to the ICEL code of practice – which is not to say they are all doing a bad job, but it is something that needs checking.

"Conversion of mains luminaires ought to be a very skilled activity and people need to do it correctly or the mains luminaires and the conversion units are likely not to work properly," notes Chris Watts of ICEL and Cooper Lighting & Security. "For example, if the battery gets overheated because the components have been rearranged, it will fail. But if the converter doesn't do the testing they won't know if it's going to overheat or not," he adds.

An important point to bear in mind is that if a standard, CE-marked luminaire is altered in any way, the CE Mark is invalidated until the luminaire has been re-tested. This means that all converted luminaires should be tested after the conversion and a new CE Mark should be applied, backed by a new Technical Construction File to support CE conformity. This can be carried out by the converter or a third party tester. The reality is that this doesn't always happen and many converted luminaires that carry the CE Mark are not up to the standard that the marking suggests.

"The majority of conversion houses do not do anything to fulfil the CE requirements," says David Wright of ICEL and Existalite. "When the luminaire comes in from the manufacturer it has been tested in compliance with the Construction Products Directive, the Low Voltage Directive and the EMC (electromagnetic compatibility) Directive.

"The conversion house will change the wiring, move components and introduce new components so if they do not carry out tests on thermal and electrical safety and EMC they cannot be sure it complies with the standards," he continues.

Testing for potential trouble
These regulations aren't just there for the sake of it. There are many ways in which conversion can affect the performance of the luminaire. It is only by testing that any such problems will be identified.

For example, if the emergency conversion unit that has been added to the fitting is not compatible with the luminaire's controlgear there may be conflicts leading to problems with operation and reliability.

Similarly, emergency luminaires need to use fire retardant components and the enclosure must comply with EN 60598-2-22 and a glow wire test of 850°C. Many standard luminaires do not comply with these requirements because they are not subject to the same stringent requirements as emergency luminaires. In addition, many modern luminaires, especially enclosed designs with multiple lamps, generate high internal temperatures.

The standard elements of the luminaire are designed to cope with these elevated temperatures, but the emergency components that have been added may not. Just a few degrees above the temperature limits for control units and batteries can have a significant impact on performance and reliability. It is only by testing that the converter can ensure that overheating is not occurring. A common example is squeezing the battery into any space that is available without testing the temperatures that the space is subjected to – and overheating is a frequent cause of reduced battery life.

This is a problem that is increasing with the modern designs of luminaires, as Grant Daniels of Zumtobel Staff Lighting points out: "As fittings become more compact, such as T5 luminaires, there is less space for the components, yet the emergency inverters and batteries have remained at about the same size. This often means that conversion requires more than just shoehorning in the emergency components. It may be necessary to rearrange the other components of the fitting."

However, as soon as you start to move the components around there is a potential for interference between them. This is a particular concern with high frequency, electronic ballasts because the leads between the ballast and the lamp act like radio aerials. Any problems with emc that arise from this will invalidate the CE Mark as the luminaire will no longer comply with the EMC Directive.

For all of these reasons it is important to take emergency lighting seriously and ensure that any conversions are carried out to the required standards. Life safety really isn't an area where the cheap and cheerful approach is acceptable. ICEL 1004 can be downloaded free of charge from the ICEL web site (www.icel.co.uk). It provides clear guidelines to ensure safe and consistent standard of engineering during modification of a wide range of luminaires.

Source

Electrical and Mechanical Contractor