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
Chesterfield is a large market town and borough in Derbyshire, England, 24 miles (39 km) north of Derby and 11 miles (18 km) south of Sheffield at the confluence of the River Rother and River Hipper. Including Whittington, Brimington and Staveley, it had a population of 103,801 in 2012, making it Derbyshire's second largest town. It has been traced to a soon-abandoned Roman fort of the 1st century AD. The name of the later Anglo-Saxon village comes from the Old English ceaster (Roman fort) and feld (pasture). Its sizeable street market is held three days a week. The town sits on a coalfield, but little visual evidence of mining remains. Its great landmark is the Church of St Mary and All Saints with a crooked spire.