Electrical wiring (UK)
Pre-1977 IEE Pre-2004 IEE
Current IEC
Protective earth (PE)
Green
Green/yellow bi-colour Green/yellow bi-colour
Neutral (N)
Black
Black
Blue
Single phase: Live (L)
Three phase: L1
Red
Red
Brown
Three phase: L2
Yellow
Yellow
Black
Three phase: L3
Blue
Blue
Grey
The modern UK standards and regulations
for electrical wiring no longer differ sub-
stantially from those in other European coun-
tries. However, there are a number of note-
worthy national peculiarities, habits and tra-
ditions associated with domestic electrical
wiring in the UK (and Ireland) that differ sig-
nificantly from other countries. These, along
with their historic background, are the focus
of this article. They include:
• ring circuits
• fused plugs
• switched sockets
• absence of normal switches and sockets in
bathrooms (except for special pull-cord
ceiling switches and "shaver sockets" with
built-in isolation transformer)
• historic wiring colours
• asymmetric supply-voltage tolerances
Legal basis
In England and Wales, the Building Regula-
tions (Approved Document: Part P) require
that domestic electrical installations are de-
signed and installed safely according to the
"fundamental principles" given in British
Standard BS 7671 Chapter 13. These are
very similar to the fundamental principles
defined
in
international
standard
IEC
60364-1 and equivalent national standards in
other countries. Accepted ways for fulfilling
this legal requirement include
• the rules of the IEE wiring regulations (BS
7671), colloquially referred to as "the
regs" (BS 7671: 2008, 17th Edition).;
• the rules of an equivalent standard
approved by a member of the EEA (e.g.,
DIN/VDE 0100);
• guidance given in installation manuals
that are consistent with BS 7671, such as
the IEE On-Site Guide and IEE Guidance
Notes Nos 1 to 7.
Installations in commercial and industrial
premises must satisfy various safety legisla-
tion, such as the Electricity at Work Regula-
tions 1989. Again, recognised standards and
practices, such as BS 7671 "Wiring Regula-
tion