LED replacement risks

A simple replacement of fluorescent tubes with LED tubes is one of the lowest cost options for energy-efficient lighting retrofits, but it can come with significant performance and safety risks, according to this information from lighting specialist enLighten Australia.

The recent extension of the Victorian Energy Saver Incentive (VEET) scheme’s commercial lighting upgrade operating hours (Schedule 34) has seen an explosion in direct selling of LED tubes, in some cases free of charge, with the installer claiming the VEEC rebates.

We have outlined the major risks below to allow building managers and owners to be in a better position to compare lighting upgrade options. In order to minimise these risks, a full luminaire replacement with either an LED batten, bulkhead, troffer or panel is recommended.

A recent acknowledgement of these risks is the decision by the NSW Energy Savings Scheme administrators, IPART, to ban T5 adaptor retrofit kits and LED tube replacements as eligible activities due to the potential hazards arising out of such retrofit installations.

Product safety and compliance risk

Safety testing and certification of non-emergency luminaires

Every luminaire sold in Australia must undergo AS/NZS 60598 or equivalent testing, which covers its classification, marking, mechanical construction and electrical construction. In addition, the NSW, SA and Victorian energy-efficiency rebate schemes require an additional Australian Certificate of Suitability/Approval as an added safety feature. This is not a mandatory requirement for product sales, but rather a requirement to participate in the rebate schemes.

Any luminaire that is modified will have altered electrical, mechanical and thermal characteristics. This modified luminaire should therefore be recertified under AS/NZS 60598 to ensure the safety of the fittings for potential electrical shock, fire or mechanical integrity risk management.

Safety testing and certification of emergency luminaires

In addition to the above, emergency luminaires need to undergo mandatory AS 2293.3 testing to gain the thermal characteristics and photometric classification of the fitting. This basically tells us if the fitting is thermally capable to house all the components and operate within temperature limits of the battery, light source and control gear. Also, it gives a classification based on the light output, which enables us to decide how far apart the fittings can be spaced, so that in case of an emergency, safe egress of the occupants is facilitated.

If a T8 fluorescent tube is replaced by an LED tube, will the newly modified or retrofitted luminaire perform under emergency conditions (ie, loss of power) as intended? This is not determined during installation. In addition, the photometric classification of the modified or retrofitted luminaire, based on the emergency lumen output, would definitely change. Does the scheme require a reassessment of the emergency luminaire spacings to reflect the new classification, ie, the distance required between emergency fittings to achieve compliant light outputs?

Electromagnetic compliance issues

Although the tubes might be separately tested for EMC compliance, once they are put into luminaires with existing control gear, there’s typically no new testing done on the modified luminaire. Safety and performance risks include higher electromagnetic interference, possible harmonics and higher inrush currents due to changed electrical and electronics of the fitting. Just checking the power factor for modified luminaires doesn’t address the EMC, harmonics and inrush current issues.

Moreover, existing fittings can have a variety of electronic/magnetic ballasts or power factor correction capacitors. Compatibility issues can cause an increased power consumption, tripping of circuits and additional loads.

Installation safety issues

It is quite possible that LED tubes are being retrofitted into very old fluorescent batten luminaires, which increases the risk of unsafe installations. For example, an average LED tube at 300–400 g is three times heavier than a fluorescent tube at 100–150 g. Modifying older fittings introduces the possibility of cracked or broken tombstones and retrofitting heavier LED tubes can cause tubes to fall out of fittings. This poses a huge risk for bare battens (battens that do not have a wire cage or diffuser) that are commonplace in car parks and fire stairs.

Product lifetime and heat management issues

The thermal performance of the modified or retrofitted luminaire cannot be predicted, as the fitting on-site could range from a bare batten to a fully enclosed IP68 luminaire installed in different environments — from a freezer room to an outside, sun-facing building facade. LED lifetimes can reduce significantly if the heat is not constantly drawn away from the LEDs.

VEET’s latest product approval requirement for an ISTMT test by a NATA accredited laboratory, as per the IES LM-84-14, is not possible on a modified luminaire with LED tube replacements. No such test is required for ‘modified’ or ‘retrofitted’ luminaires. This unduly punishes luminaire manufacturers, who are required to spend significant time and money testing their products when individual tube sellers are not bound by any such requirements.

Photometric and light distribution issues

A fluorescent tube emits lights from its entire 360° surface, while LED tubes only emit light across a 180° angle. Therefore, the photometric performance or light distribution can vary a lot from the originally intended fluorescent luminaire. For example, a suspended fluorescent fitting with upward and downward light throw used in office spaces can have disastrous lighting outcomes if fitted with LED tubes. More examples of unsuitable retrofit options include reflector fittings such as fluorescent office troffers and industrial battens.

Conclusion

The only positive outcome of replacing a fluorescent tube with an LED tube is the low upfront product and installation cost for the end customer looking for a short-term solution. While the selling of LED tubes is a matter to be assessed by the relevant electrical safety regulatory bodies, we strongly believe that modifying or retrofitting fluorescent luminaires with LED tubes should not be encouraged and incentivised further by state rebate schemes. We do not promote retrofitting existing luminaires with new lamps and control gears as the fittings were not initially designed for these new components.

Image credit: © Alexander Pastukh/Dollar Photo Club