The History of Wiring Colours & Cable Sheathings

If you’ve been in the electrical business for a while, you’ll know that the wiring colours were changed back in 2006, so what was changed and why?

The standardisation of the UK colours a decade ago was done to harmonise with the European cable colours in order to avoid confusion. Some properties throughout the UK still rely on the old cables, which can be highly dangerous if not tested. Old cable colours will either be a result of the age of the property or the wiring system, which may not have been monitored regularly.

The main changes are: what were formally black and red cables are now blue and brown, while earth is, of course, still identified by its green and yellow combination. 

When looking at cables, it’s also essential to check their condition as well as their sheathing. The average lifespan of electrical wiring is 30-40 years and will inevitably deteriorate over time, especially if a home uses one of the aged types of cable sheathing.

Before PVC-insulted cables became common in the 1960’s, most cables were made with a tough rubber sheath, which can be recognised by its black coating. Vulcanised rubber insulated cables also became popular during this time, however as it’s nearly 60 years old, it has all but disappeared in domestic homes. 

Lead-sheathed cables were also in use pre-1950s and are rubber insulated, copper conductors with an outer sheath of lead. These also deteriorate over time and should be carefully inspected if discovered. PVC insulted sheathing is now the most common form and used pretty much universally.  

When working in energetically charged environments, with potentially dangerous cables, it’s essential to feel safe and protected. Insulated hand tools and PPE are a must have for any electrician, allowing you to carry out your work with precision and ease! For more information about our reliable, safe and tailor-made tools, please take a look at our website, or get in touch with a member of the team today.