The lighting fitting illustrated below employs three protection concepts, i.e. increased safety type ‘e’, flameproof type ‘d’ and powder filing ‘q’. This type of fitting is widely used in the petro-chemical industry.
The constructional features are:
- Flameproof lampholders;
- Increased safety choke designed not to overheat if the lamp fails;
- Temperature rating based on internal and external surface temperatures;
- Enclosure sealing providing high ingress protection;
- Increased safety enclosure with certified glands
In this lighting fitting, the circuits include capacitors protected by method of protection ‘q’, powder filling. Lamp holders and cover switch are flameproof type ‘d’ and enclosure construction and terminals are increased safety type ‘e’. Similar luminaires could include components such as cover switches with protection ‘m’. E.g. Ex dem
The T class for hybrid light fittings is based on external and internal surface temperatures
