ECN Forum Forums General Topics of the Trade Non-US Electrical Systems & Trades Discussion of Legrand Wiring Diagrams

No, you adopted the French design because it was French... Although the Schuko is a poor design with obvious drawbacks, the earth does in fact make contact first.

But, indeed, I would rather have had the French sockets here.

How does the earth make contact first on a schuko plug?

According to what I understand from this document, the Germans also use TT system contrary to what you told me in a previous thread, CH, that they use, too TN system. So we are not the odd ones


[This message has been edited by Belgian (edited 10-27-2002).]

Good observations, Paul. I see you have learned some of the nuances of American wiring quite well.

Green/yellow is not representative of a typical installation. Isolated ground circuits are almost non-existent in a home. In a residence, bare would be more accurate, for obvious reasons.

#14 is never used on NEC-mandated appliance circuits.

Yes, I second your statement about multiwires. They are extremely common here and probably should be added to the diagram.

As you mentioned, red could not be feeding that water heater if Romex was used.

That diagram is also outdated, since no ground wire is shown going to the range or dryer. The practice of using the neutral for the ground on ranges and dryers is now forbidden.

BTW, I would hate to use one of your 16mm or 25m boxes. The lack of depth would drive me nuts. As it is, I dislike our 18 cubic inch boxes which are 2.5" (62mm) deep! I always use 20 or 22 cubic inch boxes, which are much deeper.

[This message has been edited by CTwireman (edited 10-27-2002).]

This is about the best summary of all these systems I've ever seen. Thanks for posting it!
Our boxes are 60mm in diameter and 50 mm deep (according to some internet source, I've got to check that some time). With that, you're already in trouble with some wall types. Many early 1900s housers here have 50 mm solid gypsum compound walls, with just about 3mm plaster on each side. I've seen elctricians saw off the back of their boxes in order to get them into these walls without ripping a hole all through the wall. Personally I wouldn't want to make too much connections inside them, but there's enough room for some block connectors.

yes of course.... taken here in a rather egotistic light if i may.... predictated on international trade, blah, blah, blah...note we've the metric system much more prononced, not that any of us really can use it effectively

>How does the earth make contact first on a schuko plug?

I tested this with a couple of sockets yesterday. The earth "rails" (can someone please tell me what I should call these?) on the side of the socket comes in contact with the metal strips on the plug about 2 mm before the live and neutral pins make contact.


You're right. The diagram really shows a TT system. And, yes, as far as I know both the TT and TN are in fact used in Germany. Legrand (French company) probably felt it more comfortable to draw a TT system.

>BTW, I would hate to use one of your 16mm or 25m boxes. The lack of depth would drive me nuts.

Same here!
We have the choice to use whichever depth we want ranging from 40 to 60mm diep. We also have special boxes for walls which are hollow eg Gyproc.

What sort of strikes me as weird is the statement in the British section that says "BS 546 sockets are no longer used in the UK."

I thought these were regularly used in the theatre industry and also for some residential lighting circuits-switched sockets (for a table or floor lamp controlled by a wall switch). At least that's what I've seen on the UseNet uk.diy newsgroup.

The purpose is to clear up the misunderstanding that BS546 are still used as general purpose sockets. Most travel sites and adaptor vendors tell you that BS 546 is just as common as the new 13A plug, and that you therefore have to buy both adaptors when going to the UK. Nobody in his/her right mind would plug in their laptop or hair dryer in a stage lighting socket. In short - these and other special sockets are used to prevent people from plugging in anything else than the intended equipment.

The same problem exist for US adaptors. Some list several of the NEMA designs, whereas you in reality will always have a 120V 15A socket to plug into. You are not supposed to plug your laptop into the tumbler socket...

Thanks C-H
I couldn't have put it better myself.
BS 546 sockets are only for special purpose use nowadays, you do not find them in general residential use.
True, 2A & 5A types can be used for lamp sockets switched from the door, but very few British homes have this arrangement.

I would point out that this guide is around 10 years old, so inevitably it will now be out of date or inaccurate.
I'm pleased it's got everyone talking!