British StandardBS 7671"Requirements for Electrical Installations. IET Wiring Regulations", informally called in the electrical communityThe "Regs", is the national standard in theUnited Kingdomfor electrical installation and the safety ofelectrical wiringin domestic, commercial, industrial, and other buildings, also in special installations and locations, such as marinas or caravan parks and medical locations
In general, BS 7671 applies to circuits supplied at nominal voltages (Uo) up to and including 1000 volts AC or 1500 volts DC. The standard therefore covers the Extra Low Voltage (ELV) range (0-50V AC, 0-125V DC), and the Low Voltage (LV) range (50-1000V AC, 125-1500V DC). The frequencies covered for AC are 50 Hz, 60 Hz, and 400 Hz, used in the UK for houses, offices, and commerce. It did not become a recognizedBritish Standarduntil the publication of the 16th edition in 1992. The standard takes account of the technical substance of agreements reached inCENELEC.
The current version is BS 7671:2018 (the 18th Edition) issued in 2018 and came into effect from 1 January 2019.Amendment 1 to the 18th Edition was published in February 2020 but the only changes were to section 722 (Electric Vehicle Charging Installations). These changes came into immediate effect upon publication release, unlike previous amendments where 6 months elapsed before changes became compliant.BS 7671 is also used as a national standard byMauritius,St Lucia,Saint Vincent and the Grenadines,Sierra Leone,Singapore,Sri Lanka,Trinidad and Tobago,Uganda,Cyprus, and several other countries, which base their wiring regulations on
Derby (About this soundlisten) DAR-bee) is a city and unitary authority area in Derbyshire, England. It lies on the banks of the River Derwent in the south of Derbyshire, of which it was traditionally the county town. Derby gained city status in 1977, and by the 2011 census its population was 248,700.
Derby was settled by Romans – who established the town of Derventio – Saxons and Vikings, who made Derby one of the Five Boroughs of the Danelaw. Initially a market town, Derby grew rapidly in the industrial era. Home to Lombe's Mill, an early British factory, Derby has a claim to be one of the birthplaces of the Industrial Revolution. It contains the southern part of the Derwent Valley Mills World Heritage Site. With the arrival of the railways in the 19th century, Derby became a centre of the British rail industry.
Derby is a centre for advanced transport manufacturing, being home to the world's second largest aero-engine manufacturer: Rolls-Royce. Bombardier Transportation are based at the Derby Litchurch Lane Works and were for many years the UK's only train manufacturers. Toyota Manufacturing UK's automobile headquarters is southwest of the city at Burnaston. To the east lies Nottingham, separated by the M1 motorway.