British Standard BS 7671 "Requirements for Electrical Installations. IET Wiring Regulations",
informally called in the UK electrical community "The Regs", is the national standard in the
United Kingdom for electrical installation and the safety of electrical wiring in 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
(o-soV AC, 0-125V DC), and the Low Voltage (LV) range (so-ioooV AC, 125-15OOV 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 recognized British Standard until the publication of the i6th edition
in 1992. The standard takes account of the technical substance of agreements reached in CENELEC.tel.
The current version is BS 7671:2018 (the i8th Edition) issued in 2018 and came into effect from i
January 2019.^ Amendment i 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 by Mauritius, 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 BS 7671.