Well first of all I want to know why the UK changed the color of mains wiring to blue and brown from black and red. My brain is STILL hard wired to think Red and Black. Likewise why is it that all the equipment I buy or DC stuff is still in Red and Black wires on the power side of things, even the DMM input leads are thus. Why did they not change everything to brown and blue !. Most annoying.
Because red and black denote DC positive and negative, whereas brown and blue denote AC live and neutral.
No, the regulations also specify brown and blue to be used for DC as well as AC in buildings.
Blue is always the earthed conductor, whether it be AC neutral or the side of the DC power supply connected to earth (which could be either positive or negative).
Grey is the negative conductor, if it's the unearthed side of the supply.
Brown is the positive conductor if it's the unearthed side of the supply.
http://electrical.theiet.org/wiring-regulations/cable-colours/harmonised.cfm?type=pdfIt was to "harmonise" us with the EU. They also made us go from nice, bright, primary colours (red yellow and blue, with black for neutral) for three phase, to brown gray and black(!) with blue for neutral. RYB were easily identifiable in a dark owered down panel, brown gray and black, not so.
I've never understood the purpose of harmonisation with the EU for fixed wiring. It's fair enough if the wiring is in a product which is being exported to the EU but it's none of their business what colour the wires are inside fixed installations.
Perhaps it was done to keep the European cable manufacturers happy so they can sell to the UK?
I know it is illegal to install anything mains without a PAT test here in the UK now, I went ahead and installed a power shower.
No, it's nothing to do with PAT which is portable appliance testing and doesn't cover fixed wiring such as a shower. Fixed installations need to comply with part P.
http://en.wikipedia.org/wiki/Electrical_wiring_in_the_United_Kingdom#Legal_and_regulatoryIn reality there's no real way of policing this, as long as you don't do anything dangerous then you'll be fine.