Have a question for Pauluk. Installed a piece of machinery (a small English made 1-phase metal-lathe) in a School earlier this week. The machine was equipped with a flexible 3-wire cord, with the colours black, white and green. Black and white was used for phase, and neutral and green (not green/yellow just green) was the ground wire. Is this colour combination common in the UK?

Kent,
the colour code you give is not normal for the UK in any way.

The normal colours are the following;

single phase, (one hot), flexable cable,

brown = hot
blue = grounded conductor (neutral)
green/yellow = grounding conductor, (earth)

three phase, (three hots) flexable cable,

red = phase # 1
yellow = phase # 2
blue = phase # 3
black = grounded conductor, (neutral)
green/yellow = grounding conductor, (earth)

the colours you say were,
black = phase #1
white = grounded conductor, (neutral)
green = grounded conductor, (earth)

very odd, was the whole unit manufactured for export ? if it was i can see why the colours were that way, but if it was for UK use they could not sell it as the codesd say that the colour codes must be within the requirements for cable identification.
can you give any further information on the manufacturer ?

Thanks, John

The machine must have been intended for the North American market, as the colour code you describe has never been used in the UK.
However black, white & green are the standard colours used for single phase 120V applications in the US.
Since the early 1970's all single phase appliances sold in the UK have the standard international code: brown (phase), blue (neutral) & green/yellow (earth).

Thanks guys. You are properly right. I recall bumping into a another piece of machinery with the same type of cord and colours and that one was US made. Think the cord to the lathe was made by Royal Cable... something. It sounded very British to me but maybe it’s an American company?

Hi Kent,

Haven't heard from you in a while -- Welcome back!


I've never heard of the Royal Cable Co., but as the others have said, black/white/green is the North American standard.

Single-phase British cords have followed the European standard brown, blue, green/yellow since 1970. Prior to that they were red (line), black (neutral), and green (earth/ground).

I googled a little bit and found the following:
>Royal Cords are cords used in applications where flexibility is very important. They are used in rugged applications such as vacuum cleaners, motors, portable tools and others where there is constant
movement. Construction is copper followed by PVC insulation, then PVS bedding and a final PVC sheath.
These cords are manufactured by Marton Wires & Cables, Manila, Philippines. http://www.marton.com.ph/index.html

Paul said ...

"I've never heard of the Royal Cable Co., but as the others have said, black/white/green is the North American standard."

Could it be Canadian?

if you guys are wondering about Royal Cable Co. that is a amercian made cables they do make wide varites of cables for differnt useage but unforetlay i dont have thier web address but i will keep my word to keep digging in to get the info then i will post it here

merci marc