Ex q Powder Filling Explosive Atmospheres

The Ex q Powder Filled Standard of explosion protection states that all equipment that has the potential to arc is contained within an enclosure filled with quartz or glass powder particles. This powder filling prevents the possibility of an ignition. When the enclosure is filled with the powder-type medium (quartz sand, powder or glass beads) there must be no voids within the enclosure.

The hazardous area enclosure construction requirements are a pressure test of 0.5 bar (1 bar = 14.5 psi) overpressure for 1 minute and, if not protected by another enclosure, a minimum ingress protection of IP54. If the components are protected by another enclosure, for example, a capacitor with the Ex q type of protection built into a light enclosure, then no specific requirements for the type of ingress protection are required

Equipment using this Powder Filled explosion protection method is suitable for use in both Zone 1 and Zone 2 hazardous areas.

 Explosion Protection Principle
By filling the enclosure with a finely grained powder, an arc within the enclosure is unable, with correct use, to ignite the explosive atmosphere outside. There must be no risk of ignition by flames, nor by increased temperatures at the surface of the enclosure.

 Important Design Parameters

·         The Ex q filling such as sand, glass balls etc. has to fulfill specific requirements, as must the design of the enclosure

·         The powder filling medium must not be able to leave the enclosure, neither during normal operation, nor as the result of electric arcs or other processes inside the powder-filled enclosure

Ex q Powder Filled Applications
Capacitors, electronic assembly groups or transformers which are used in a potentially explosive atmosphere. Often components where sparks or hot surfaces occur but whose functioning is not affected by the finely grained filling

                             Type Of Protection To Electrical Equıpment

Type of Explosion Protection	Powder filling Ex q – EN IEC 60079-5
Explosion Protection Principles	Protection principle prevents propagation of flames using an enclosure
Flammable Material	Gas/vapour (G)
Category 1 EPL a – Very High Level of Explosion Protection	–
Category 2 EPL b – High Level of Explosion Protection	Ex q Explosion Protection
Category 3 EPL c – Normal Level of Explosion Protection	–