What colour are plus and minus?

[WaldemarL]

I used to work in Russia, and there we always used wire with red isolation for + and blue or black for -. Now I am workink for one german company and here is blu for + and brown for -. What are the rules or traditions for other countries?

 

[zeitghost]

In the UK, for low voltage d.c. applications it is generally red for + and black for -.

For single phase domestic mains wiring in the wall it is red for live, black for neutral and green/yellow striped for ground. (The ground wire is bare in the 3 core cable with a green/yellow sleeve inserted in the patress i.e. the box behind the socket).

For the cable from the equipment to the wall socket, the colour code is brown for live, blue for neutral and green/yellow for ground.

Confusing isn't it?


rgds
Zeit.

 

[Skogsgurra]

I have always told the newbies that "Black is red and plus is minus". If they nod knowlingly I know that they did not listen.

I got caught in my own trap this week when one of these guys got confused about plus and minus and inadvertently connected a transducer the wrong way. Result: an eight meter wide and 1000 m/min paper machine stopped.

So don't make jokes about these things. It could cost a lot more than it is worth.

I always use black for zero volts. Blue for -12/15 V and red for +12/15 V. If there are other voltages I use orange for the positive (say +24 V) and violet for the negative (say -24 V).

There is a problem here. An ordinary european electrical installation normally uses black for phase (L) and light blue for neutral (N). This can cause unpleasant results - and have done so. I once had a security system installed by a "lamp electrician", not industrial) and sure enough, he wired the zero with blue wire and the positive with black. It created some confusion and also some damage.

 

[Degory]

This is a question that is I have been tasked as to color coding of power and grounding(return) in electrical circuits.
Does anyone have any documentation on identifying the power and return circuits?

 

[lcsjk]

You are referring to international product safety standards. Search the internet for
"product safety" and words like ISO, UL, CSA, CE, TUV, VDE, DEMCO. This gets most of the main worldwide usage for standards.