BS 5620 is a British standard that specifies the constructional and test requirements for 200 A flameproof restrained and bolted plugs, sockets, and plug coupling units suitable for single voltages of 650 V and 1 100 V and dual voltage of 650/1 100 V. They are primarily intended for use with mining apparatus which is connected to its power supply by means of a flexible cable.
Three types are covered in BS 5620 and designated as:
Type 1 and 2 configurations are not interchangeable. The plugs, sockets, and plug coupling units incorporate three power contacts, a pilot contact for electrical interlocking, and a scraping earth contact. The dual voltage plugs and sockets are intended for use either on a 650 V or 1 100 V supply, the appropriate arrangements including a selection of voltage by the orientation of insulator and pins to ensure non-interchangeability for other than the appropriate voltage.
Note: The figures in BS 5620 show only those features and dimensions essential for function interchangeability.
BS 5620 on bolted plugs and sockets used in coal mines is useful for:
BS 5620 continues to ensure the interchangeability of plugs in sockets of different makes and to standardize the fixing dimensions of sockets. This ensures dependable connections and high resistance, also in aggressive atmospheres. BS 5620 provides you with the information and requirements to be agreed upon and documented, insulation, and specifications for the terminals, plugs, and sockets. BS 5620 also guides you with test methods for routine assessments and markings. Using BS 5620 guidelines ensures performance, safety and protection, quality assurance, reliability, and durability of the equipment for longer and safer service life.