Restriction of Installation

Types of lamps in Ex e and Ex n luminaires #

There are restrictions in the IEC60079-14 installation standard on the type of lamps fitted in ‘Ex e’ and ‘Ex nA’ lighting fittings (luminaires).

Luminaires with fluorescent lamps and electronic ballast in types of protection Ex ‘e’ or Ex ‘nA’ shall not be used where temperature class T5 or T6 is required or where the ambient temperature exceeds 60°C.

This restriction minimises the risk of the end of life (EOL) effects of lamp.

Lamps (e.g. bi-pins, screw connections on tungsten lamps) using non-conducting materials with a conductive coating shall not be used, unless tested with the equipment.

This restriction is intended to apply lamps where the pins or end caps could be plastic or ceramic with a conductive film coating.

For lamps with pins, the pins shall be made of brass.

Light metals #

The installation of equipment in hazardous areas may involve the use of metallic mounting brackets, cable tray, weather protection etc. It is important that the light metal content of such items does not exceed the following limits relative to the EPL requirements for different locations.

EPL Ga locations

Total content of aluminium, magnesium, titanium and zirconium – 10%, or

Total content of magnesium, titanium and zirconium – 7.5%

EPL Gb locations

Total content of magnesium and titanium – 7.5%

EPL Gc locations

No limitations

Static electricity on non-metallic materials #

The use of non-metallic installation materials such as plastic covered cable tray, plastic mounting brackets and plastic weather protection can create an unacceptable level of static electricity if measures are not implemented to control this. Static electricity is capable of igniting flammable gases/vapour and therefore has to be controlled.

The initial approach to the control of static electricity is the selection of material having an insulation resistance not exceeding 1GΩ.

Alternatively, the surface area of non-metallic parts may be limited in accordance with the table below, the surface area limit being dependent on the EPL requirement for the location and the gas group.

The dimensions in the above table may be increased by a multiple of 4 if the non-metallic material is surrounded by a conductive earthed frame.