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TUKES writes about the use of LED light tubes

Converting a fluorescent lamp to an LED light tube

The following discusses responsibility and safety issues related to the use and installation of LED light tubes. There are several factors to consider when introducing LED light tubes. Several new safety risks can be associated with LED tubes and lighting changes that may be made in their installation for both consumers and electrical professionals. 

Where LED light tubes are used

Led light tubes are mainly used as replacements for T8 (T5) fluorescent tubes in G13 (G5) base fluorescent tube lamps. There are also lamps on the market specially designed for LED tubes, in which LED light tubes are installed as initial installations. Typical applications of LED light tubes include e.g. industrial production facilities, public facilities, shops, warehouses, parking garages, cold rooms and equipment. The aim is to achieve cost savings in lighting with smaller input power led light tubes.

The safety of LED light tube installations 

When making LED light tube installations, it must be ensured that the change from a traditional fluorescent tube to an LED light tube (and vice versa, if necessary) under no circumstances endangers safety or weakens the electromagnetic compatibility of the installations. The LED light tubes to be installed must be safe, and the necessary installation and modification work must be done in accordance with the given instructions.

Two types of led light tubes

There are mainly two types of LED light tubes on the market: retrofit LED light tubes and LED light tube conversion kits. Retrofit led light tubes can be installed in existing fluorescent lamps without making any changes. This installation work can be compared to maintenance work. In conversion kits, the installation of an LED light tube, on the other hand, requires modifications to the original fluorescent lamp and its components in accordance with the instructions. In this case, the safety of the changed lamp and the new installation must always be ensured. 

Retrofit led light tubes (retrofit installations)

The LED light tube can be of the so-called retrofit type. The retrofit led light tube can be installed in a fluorescent lamp without any changes to the original lamp (taking into account the possible tube model and lamp-specific restrictions stated by the manufacturer).

Luminaires suitable for the retrofit installation method usually have a magnetic current limiter or choke. In retrofit installations, the fluorescent tube lighter must also usually be replaced with a so-called LED lighter (with a short circuit piece). Replacing the lighter of a fluorescent lamp with an LED lighter is not considered as changing the design of the lamp. However, the use of an LED lighter must not cause a decrease in the safety level, and it cannot be the only essential safety component for a new LED light tube installation (a LED lighter with a fuse).

Legal requirements

The retrofit led light tubes on the market must meet the requirements regarding safety and electromagnetic compatibility set for them in the legislation. The LED light tube must have a CE mark as an assurance given by the manufacturer that the LED light tube meets the requirements of all directives concerning it. The Low Voltage Directive (2014/35/EU), the EMC Directive (2014/30/EU), the RoHS Directive (2011/65/EU) and the Ecodesign Directive (2009/125/EC) apply to LED light tubes, to which the EU declaration of conformity drawn up by the manufacturer should be referred to. The detailed safety, installation and use instructions must be followed with the Retrofit LED light tube, according to which it is safe to install and use the tube. Safety standard SFS-EN 62776:2015 applies to retrofit led light tubes. 

Retrofit led light tubes must be compatible with the standard fluorescent tubes used in fluorescent lighting in terms of various applicable technical characteristics, such as the weight and dimensions of the tube, the operating temperature of the tube, and several electrical and electromagnetic properties. 

Liability issues

If safety risks arise in retrofit installations carried out according to the instructions, or if electromagnetic disturbances increase after the installation of retrofit led light tubes, the responsibility for this lies with the economic operator (manufacturer, importer, distributor) who has made the retrofit led light tubes available on the market.

In the retrofit installation method, the CE mark and other certification marks of the original fluorescent lamp remain valid. The lamp can be returned to fluorescent tube use by only changing the LED lighter back to a fluorescent tube lighter.  

Led light tube conversion kits (conversion kits)

The LED light tube can also be delivered as part of a conversion kit. The conversion kit contains all components (e.g. ballasts, control electronics, lamp holders and wiring) as well as detailed installation and testing instructions, which can be used to convert a fluorescent lamp into a functional LED light tube lamp.

In conversion kits, the installation of an LED light tube always requires changing the structure of the original fluorescent lamp. Such changes include e.g. changing, replacing or removing ballasts and internal wiring. After the changes, the original manufacturer of the lamp is no longer responsible for the safety or other characteristics of the lamp. Also, the value plate, CE mark and other certification marks put on the lamps by the original manufacturer are no longer valid.

Responsibility for safety and compliance

The person putting the LED light tube conversion kit on the market must make sure that the result of the modification work carried out in accordance with the instructions is a safe and electromagnetically compatible LED light tube lamp. There is no separate safety standard for the LED light tubes of the conversion kits. The manufacturers, importers and distributors of the sets must make sure that the new entity created as a result of the modification work carried out in accordance with the instructions is safe and compliant.

In general, LED light tube conversion kits are subject to the same requirements as retrofit LED light tubes. The modification work must not in any sense weaken the safety of the lamp. The modified lamp must remain safe, even if a T-type fluorescent tube is accidentally installed in it (the fluorescent tube does not have to work). The manufacturer of the modification kit is not responsible for modification work done contrary to the instructions.

The instructions given by the seller of the LED light tube conversion kit must contain information about the types of lighting that are suitable for the to change work. It should be clearly stated in the instructions that the conversion work can only be done by a professional in the electrical field and that a warning/notation must be placed on the lamps that they have been converted to use LED light tubes. 

Changes to fluorescent lamps 

When installing LED light tubes in fluorescent lamps, lighting changes may also be desired when using retrofit type LED light tubes. Lamp changes often have to be made also when using other types of separately sold LED light tubes (e.g. first-installation LED light tubes intended for LED light tube lamps). 

For example, by removing the magnetic ballasts of the lamps, power losses can be reduced, and by removing the compensation capacitors, the power factor can be improved. With the modifications made, the original manufacturer's responsibility for the lamp ceases, and the responsibility for the safety and other compliance of the new lamp is transferred to the person who made the modifications. The markings on the lamp are also no longer valid and must be replaced by the person making the change. 

If the owner of fluorescent lamps already in use makes the necessary changes at the place of installation of the lamp himself or makes the necessary changes at his own responsibility and the resulting lamps are not put on the market (sold or otherwise given away), new lamps created during the modification work do not need to be CE-marked (the lamp remains part of the fixed installation).

The person making the change must ensure safety

New lighting fixtures (made modifications) must comply with the requirements of Finnish electrical safety legislation, i.e. lighting fixtures must be built and manufactured in such a way that they do not cause danger to people, domestic animals or property and that they do not cause electromagnetic interference and their operation is not electromagnetically disturbed. The changer must ensure the electrical safety and electromagnetic compatibility of the changed lamps. At its simplest, the converted fluorescent lamp only has the frame, partial internal wiring and lamp holders. Ensuring compliance with the requirements of the electrical safety legislation is done on a case-by-case basis using measurements, component test results, standards, etc. As an aid in pointing out, the SFS-6000 series installation standards, the SFS-EN 60598 series lighting standards and the EMC standards for lighting can also be used if necessary (EN 55015, EN 61000- 3-2, EN 61000-3-3 and EN 61547).

Marking for changed lamps

A clear warning and/or marking must also be placed on the modified lamps that they have been modified for use with LED light tubes. In the same way, the person doing the modification work must attach the contact information of the person performing the modification work (responsible party) and a new rating plate to the lamps. The changes made and the verifications/measurements carried out must be documented and the documents handed over to the owner of the lamps/the person performing the change work. The modification work must be done by a professional in the electrical field.

If new (modified) lamps are put on the market (sold, loaned, rented, leased or donated), the person making the changes (manufacturer) must carry out or carry out conformity assessment procedures for the new lamp in accordance with all relevant directives, prepare technical documents and an EU declaration of conformity and equip the product with a new with nameplate and CE marking.

Things to consider in LED light tube installations

Using LED light tubes in traditional lamps, which were originally designed for standard T-fluorescent tubes, can result in the lamps producing a significant amount of reactive power to the network (the power factor can be very poor). In the worst case, this can lead to a significant increase in the total current and thus cause additional heating of the conductors of the lighting group. 

Removing the compensating capacitors in the luminaires usually improves the situation (power factor), but in this case the factors related to the luminaire change to be made must be taken into account. Especially in large lighting groups, it is always necessary to make sure that the introduction of LED light tubes does not cause problems for the overall safety of the lighting installations and that the effects on possible centralized compensation devices are also investigated. It is also necessary to make sure that the new installation does not cause an increased harmful 3rd surge current to the neutral conductor. In the installations, you must also follow any additional instructions given by the manufacturer of the LED light tube, e.g. regarding the maximum number of LED light tubes connected to one group.

Source: TUKES