Protection classes of luminaires and operating devices

The degree of insulation against electrical shock offered by luminaires and operating devices is split into two safety levels. These two safety barriers are designed to prevent any risk to safety in the event of a defective device, i.e. they cannot become live.

Luminaires and operating devices of protection class I provide protection against electrical shock solely using the base insulation and the safe connection of all exposed conductive parts to an earth conductor. Thus, should the base insulation fail, no exposed conductive parts can become live.

Luminaires and operating devices of protection class II provide protection against electrical shock using both the base insulation and an additional or reinforced insulation. Protection class II products do not feature a connection to a protective earth conductor. (In special cases a device can feature or be required to feature a functional earth, e.g. for EMC reasons, or a continuation of the protective earth conductor in a luminaire.) The mounting conditions do not ensure any additional degree of protection, either.

In special cases with Protection Class II luminaires, it can be permissible to connect a protective conductor or a function protection conductor, as follows:

• for EMC reasons – in such cases, it can be necessary to connect a function protection conductor to remain within EMC limiting values. The component manufacturer´s specifications regarding the individual operating devices must be observed during the construction of the luminaire. If an operating device is marked as containing a function protection conductor, the creepage and air clearance distances of the operating device connection must comply with the requirements of protection class II (reinforced or additional insulation);
• as an ignition aid for lamps – connecting a function protection conductor can be necessary as a capacitive ignition aid for lamps. In such cases the creepage and air clearance distances around the ignition aid within the luminaire and the function protection conductor connection terminal have to comply with the requirements of protection class II (reinforced or additional insulation). The ignition behaviour of a lamp should be agreed with the manufacturer in these cases;
• when wiring the protective conductor from the luminaire to another device. This is an installation point of the protective conductor and creepage and air clearances must comply with the respective requirements laid down in the luminaire standard as well as any requirements regarding reinforced or additional insulation.

Operating devices with double or reinforced insulation for installation in protection class II luminaires

Protection class II specifications have to be met by the luminaire along with its installed operating device. Both protection class I and class II ballasts can be installed. The design of the luminaire must be adapted to suit. This means that if a protection class I ballast is installed in a protection class II luminaire, the design of the luminaire has to be correspondingly sophisticated to ensure the cree-page and air clearance distances can be met. On the other hand, using a protection class II ballast, only available as an independent ballast nowadays, will in most cases result in a need for too much technical effort and thus in high costs. Against this background, the standards contain special requirements for ballasts destined for installation in protection class II luminaires.

These "double or reinforced insulation ballasts" permit technically and cost-effective construction of protection class II luminaires.

Protection class III luminaires provide protection against electrical shock by using Safety Extra Low Voltage (SELV). Luminaires of protection class III are not permitted to generate higher voltages than the Safety Extra Low Voltage (SELV).

Protection Classes of Luminaires and Operating Devices

IEC 60529 (EN 60529) defines protection classes for enclosures of casings. The IP Code (International Protection Code) describes the level of protection provided against accidental contact and penetration by foreign bodies as well as protection against water. The first number stands for protection against foreign bodies, the second stands for protection against water. These specifications are important with particular regard to built-in or mounted luminaires as the provisions governing protection against accidental contact provide the basis for the insulation system for components and conductors (also see luminaire standard EN 60598).

To comply with the IP requirements, the installation instructions supplied by the luminaire and/or operating device manufacturer(s) must be observed.

Number	1st Number		2nd Number
Kennziffer	Protection against contact	Protection against foreign bodies	Protection against water
0	No protection	No protection	No protection
1	Protected against contact with the back of the hand	Protected against solid foreign bodies Ø > 50 mm	Protected against vertically dripping water
2	Protected against finger contact	Protected against solid foreign bodies Ø > 12 mm	Protected against diagonally dripping water (angle of 15° from above)
3	Protected against contact with tools	Protected against solid foreign bodies Ø > 2.5 mm	Protected against diagonal water spray up to an angle of 60° from above
4	Protected against contact with wire	Protected against solid foreign bodies Ø > 1 mm	Protected against water splashes from any direction
5	Protected against contact with wire	Protected against dust	Protected against jets of water
6	Protected against contact with wire	Dust-tight	Protected against strong jets of water
7	–	–	Protected against temporary immersion in water
8	–	–	Protected against permanent submersion in water. Specific testing conditions must be agreed, especially with regard to high- pressure cleaning equipment.
9	–	–	For high-pressure cleaning IPx9 in accordance with DIN 4005

If any components like ballasts or conductors of built-in or mounted luminaires (e.g. wall-mounted luminaires) are accessible to accidental contact, they must comply with the requirements of the two safety levels stipulated for these components. Luminaire construction must be in line with these conditions, which can mean that, for instance, conductors have to feature additional or reinforced insulation.

A different approach is taken with regard to lampholders, for which compliance with the two safety levels is proved by conducting a special voltage test.