Hello Guys,
after being away for a while, i'm back to the forums and i have posted some pictures here, more to come:
http://www.electricalphotos.com/showgallery.php/ppuser/70/cat/500

feel free to talk to me about them

An interesting collection of photos there Andy -- Many thanks for posting them.

Looking at these two from the old power plant:

http://www.electricalphotos.com/showphoto.php/photo/695
http://www.electricalphotos.com/showphoto.php/photo/698

It appears that the phases were identified as green, yellow, and purple. Was that a standard color code in Germany at one time?

Also on colors, what's the green wire in this photo?

http://www.electricalphotos.com/showphoto.php/photo/728

I know the old German system was black=L, gray=N, red=E. Is the green a newer addition, or used for some other purpose at that time, such as switch loops?

I also notice from several pictures that bonding (newer wiring) all appears to be done in double-insulated cables (green/yellow with outer gray sheath):

http://www.electricalphotos.com/showphoto.php/photo/738

Is that standard practice in Germany now? Here we would usually only use single-insulated cable for bonding.

And finally for now, looking at the switch/socket combo here:
http://www.electricalphotos.com/showphoto.php/photo/751

It appears that you have to carefully align the faceplate after wiring so that the side earth contacts correctly seat within the slots. It looks kind of tricky -- Or is it one of things which just becomes easy when you're doing it all the time? (Like opening the shutters on U.K. sockets with your meter probes!)

Hello Paul,

i will begin to study in Wrexham in September and i'm excited to see UK electrical things

The power plant bus bar colors and the green wire in that box belong somewhat together.
It seems to me there were 2 different color codes used at the same time. One was black - black - blue and the other one was yellow-greenn-purple for L1,L2,L3. I have seen yel-gn-pur in substations mostly, not in houses. I will try to find out more. In the house where the wirenut picture is from, they used yellow for switch to lamp and green for light relays interconnection.

Double insulated bonding cable: It is permitted to use single insulated gn/yel wire, also fine stranded ones, if it's in a pipe or raceway in or on a wall with only short portions uncovered (i.e. round a corner) and no danger of damage. Runs on a wall with clips like the picture shows (and a bit too much distance between clips...) demands for double insulated.

Switch/Socket combo: yes, you have to align the modules to each other. Thats easy by aligning the sheet metal frames together. The Cover Frame is held in place by a clip that goes into these 2 round holes at the switch, and by the socket cover itself at the socket. The GND bars help to get the socket cover on and find the thread for the fixation screw in the middle. That's pretty easy after youve done it 5 times.

oh, editing time has expired. in the part about bonding wires, it must be "e.g. round a corner" instead of "i.e." of course

Nice photo's you have added there from Germany.

Interesting to see that on the domestic switchboard photo, that the new "harmonised" colours have been adopted for the phases.

Black, Grey, Brown (Phases) and Blue for Neutral.

In The Netherlands (where I originally come from) we used Brown for all three phases or Brown, Black, Black with white dots. (Pre 1988)

These new colours were adopted in the UK about 3 years ago

Gruß, Raymond

Green yellow purple was used for distribution, black blue black for residential wiring at least where 5 core cable was used. Other than that phases could be about any color even grey and red (usually neutral and ground). Where conduit was used people typically pulled all 3 phases the same color.
In residential wiring green, yellow and other colors were often used for switch legs, travelers and other special purposes.

The double insulated ground wire seems to be typically German, Austria uses single insulated as far as I know.

Yes, aligning devices in the boxes is somewhat tricky. I guess the worst thing is 6 2.5mm2 wires in one box for daisy chained sockets. Some time I'm going to try Italian wall boxes with Schuko sockets, I think that might be easier to wire.

Interesting photos, I like the architecture of the substation. Very well blended in, even if it's been in disrepair for a long time.

I just notice now and again you get Irish posters on various UK DIY sites and they're getting wrong advice re: core colours.

Great fun!

There's a lot to be said for European standardisation, even if we like the quirks of our old national systems. At least you don't end up with a French oven with french terminal colour markings, wired incorrectly to UK colour cable wired incorrectly to an Irish house

Have a look through the old threads in this non-U.S. area of the forum, and in some of photo areas, and you'll find plenty of pictures of U.K. fittings, past and present. That might give you a start in identifying some of the things you'll see here.



It seems curious to have adopted two such totally different color codes for the same thing. If there was a reason such as distinguishing between two different voltage levels in the same installations (e.g. like the U.S. convention of black/red/blue for 120/208 and brown/orange/yellow for 277/480) then I could see the sense.

And why black/black/blue? If you're going to identify the phases at all, why not identify all of them, not just one?

That was one of the issues in the new "harmonized" scheme which resulted in gray being adopted, largely at British insistence. Without our intervention, it seems likely we would have ended up with brown/black/black or brown/brown/black instead.



The problem with introducing any new system though is that it doesn't suddenly replace the existing systems, but instead just adds another scheme into the picture.

You can still find red/white/blue phase colors in use here, even though the B phase was changed to yellow in the mid 1960s. And seeing as we were installing red/yellow/blue until just a couple of years ago, I think different color schemes between the existing cabling and new equipment are going to be around until at least the mid 21st century.

It is interesting to see how other parts of the world do their wiring. I was in Europe last fall. I was surprised to see that Europeans using cable instead of conduit even in large commercial applications. That takes a bit of prior planning. Since they like using concrete to build everything, it is not all that easy to add to later.

One of the intersting things I saw while there was my daughter and son-in-law's military housing that was wired for both European 220V 50 Hertz and US 120V 60 Hertz. This was smart wiring. Back in the day when I was stationed in Germany, It was all 220 so you had to buy the stuff over there and sell it when you left if it was not duel rated.

The other thing that's a little weird is that different countries seem to employ differing levels of regulation on the use of the colour codes e.g. here's how it's implemented in Ireland :

New Harmonised European Cable Core Colours

The new European harmonised core colour code for multi-core cables will be mandatory in new electrical installations certified on and from 1st April 2006. Before that date, wiring in new installations, including extensions, may use either the existing colour code or the new harmonised colour code. The new three- phase core colours are brown, black and grey, with blue for neutral and green/yellow for the earth/protective conductor

The following limitations apply:

1

Green/yellow cores shall be used only as protective conductors and shall not be converted e.g. by sleeving for use as neutral or line/phase conductors

2

Blue cores shall be used only as neutral conductors and shall not be converted e.g. by sleeving for use as protective conductors or line/phase conductors

3

Brown, black or grey cores shall be used only as line/ phase conductors, and shall not be converted e.g. by sleeving for use either as protective conductors or as neutral conductors

4

Where more than one conductor in a multi-core cable is fed from the same phase, both shall be identified by the relevant phase colour, using sleeving as needed

5

For single-core cables used for three-phase circuits, the core colours shall be the same as for multi-core cables

6

Where single-core cables are used to supply single-phase circuits fed from a three-phase distribution board, the respective line/phase conductor colour may be extended to the single-phase circuits fed from that phase

7

Sleeving or tape used for identification purposes shall be permanent, heat resistant, colour-fast, non-conductive, and shall comply with EN 60454 or other appropriate standard

8

Four-core cable without a blue core e.g. NYM-J shall be used only for circuits with balanced three-phase loads e.g. three-phase motors

pauluk: the yel-gn-pur colors were used on the primary side in substations, too (20kV). maybe they did it that way to avoid mixed color codes in their switchgear.
at least it was a code to clearly identify each phase.
Before the new gray phase conductor, some used the sequence of wires in a cable to identify each phase in black-black-brown, but not everybody. In the company where i did my apprenticeship, we used the black one between gn/yel and blue as L1, the brown one as L2 and the remaining black one as L3.
Thus leading to another confusion, as now brown is L1, not L2 anymore.....

Sadly I think not everyone here today goes strictly for the brown-black-gray sequence, I believe it's just a "recommendation" here. At least they check for correct phase rotation more often nowadays.

djk: Those rules sound quite like the German ones, but I believe we have one exception for the blue wire. In a 3-wire cable brown-blue-gn/yel to a single switch, I believe the blue one may be used as switch return. It was that way a few years ago, I'll check if it's still OK.

It is a little surprising to see that a modern country such as Germary not standardrizing the coloring. In the U.S. there is a few requirements but for the most part, the coloring system is standardized but not required. For the most part no matter where you go in the US, you open a panel and you will see the standards followed. Makes a job a whole lot easier.

Well, nowadays colors are standardized as far as cable is concerned.

There are a few exceptions though. Where a neutral is present it has to be blue and the only blue wire. Where no neutral is needed and present the blue wire can be used as a phase conductor (frequently done for switch loops).

Austria does allow the grey conductor of 4 core cable to be re-identified blue and used as a neutral.

Where conduit is used (very common in Austria) the core colors are merely recommendations - only yellow/green and blue are limited to ground and neutral, phase conductors can be any color but green, yellow and yellow/green. Typically electricians pull three black wires for the phases.

Don't ask me why, but Germany loves cable... they seem to think conduit is old-fashioned. Austria is just the other way round - our sparkies think burying cable in masonry or concrete is barbaric. With this opinion Germany seems to be pretty much alone in Continental Europe, almost all other countries I have visited so far prefer conduit.

The yellow-green-purple color scheme was only used for distribution, both medium and low voltage, sometimes up to the panel of a house or apartment. In this scheme they even took the phase colors serious, I've seen a 1955 apartment building where each apartment was fed with either yellow, grey and red, green, grey and red or purple, grey and red. From the panel onwards they continued with black phase and neutral, no ground...

A similar limitation is found in BS7671 -- Green/yellow cores may not be re-identified for any other purpose than earthing.





However, BS7671 contains neither of these limitations.

Basically, you may not re-identify a green/yellow wire to use it for something other than an earth, but you may freely re-identify any other color if you wish.

So a blue on switch loop is sleeved brown to use as a return. If you are using 3-core (e.g. SWA) which has the brown/black/gray phase colors, you can leave the brown as is to use as the phase, then sleeve the other two conductors in blue and green/yellow for neutral and earth.

This basic principle hasn't changed from the old color code, e.g. red sleeving on black to use as a phase, black sleeving on a blue to use as a neutral, etc.



That's an interesting one, since strictly speaking the I.E.E. Regs (since long before they became BS7671) have said that a single-phase circuit derived from 3-phase should always use the "basic" live color -- Formerly red, now brown. Use of the other phase colors (yellow & blue, now black & gray) is permitted on a single-phase branch feeder up to the final distribution panel though.