Basic Electrical Installation Work

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Strana 282 z 399

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Petrol filling pumps must wired and controlled flameproof equipment to meet the requirements the Petroleum Regulation Act 1928 and 1936 and any local licensing laws concerning the keeping and dispensing of petroleum spirit. ● Zone the most hazardous, and defined zone area in which explosive gas–air mixture continuously present pres- ent for long periods.5 Flameproof equipment markings. All certified flameproof enclosures will be marked Ex, indicating that they are suitable for potentially explosive situations, EEx, where equipment certified the harmonized European Standard.5, if the integrity the wiring system maintained. All the equipment used flameproof instal- lation must carry the appropriate markings, shown Fig. These have longer gland thread than normal MICC glands the type shown Fig. Where the cable laid underground, must protected PVC sheath and laid depth not less than 500mm. Hazardous area classification The British Standard divides the risk associated with inflammable gases and vapours into three classes zones.Statutory regulations and codes practice 271 a hazardous area must flameproof fittings using appropriate method, such as: ● PVC cables encased solid drawn heavy-gauge screwed steel con- duit terminated approved enclosures having wide flanges and bolted covers. (‘Long periods’ usually taken mean that the gas–air mixture will present for longer than 1000h per year. ● PVC armoured cables terminated into accessories with approved flameproof glands any other wiring system which approved by the British Standard. 13. ● Mineral insulated cables terminated into accessories with approved flameproof glands. Flammable and explosive installations are found the petroleum and chemical industries, which are classified group industries. 6. Mining is classified group and receives special consideration from the Mining Regulations because the extreme hazards working underground.3 Chapter this book. .) X FIGURE 13