ECN Forum Forums General Topics of the Trade Non-US Electrical Systems & Trades Some german electrical info

Re reduced-size earth conductor in UK cables -- Sorry, I goofed. Shouldn't post when I'm tired after a hard day, and it seems to have been all go the last three or four days.

You'll see multiple neutral conductors under one screw terminal all the time here. Where the neutral bar has only as many terminals as there are circuit breaker positions, it's unavoidable with the use of ring circuits.

As we've discussed in other threads, I think too big a deal is made of polarized plugs for most portable appliances in Britain. Looking around the electric tools and test equipment surrounding me at the moment, I can see very little where polarity is of any consequence at all.

Here in the USA putting two conductors under a single terminal screw a big no-no.

If the inspector sees that, you will be tagged. There's something also in the US National Electrical Code about it, I think, from what I've gathered here.

Someone who has the code might be able to check what chapter/verse?

It depends on how the terminal screw is designed. If it has space and a big flat head and the cables are put carefully under it and it's tightened properly they'll hold and make good contact for years. If not you're in trouble!

Paul: Generally in UK domestic installations you use quite small Consumer Units / Boards? i.e. just a single DIN rail?

Most of the rest of Europe, including Ireland, tends to use much more spacious boards. Typically here they're at about 30cm by 30cm (very aprox. I'm not 100% sure of the current dimentions that's just a rough eyeballed guess!) But you'll get two rows of MCBs in.

Some 1970s installations tend to be all Ring circuits or 2 rings and 1 lighting circuit so you just have 3 big diazed fuses and 1 smaller one for lights.
That way of doing things doesn't seem to have remained common practice however. We seem to have switched back to radials again despite not being legally required to for any reason. I think many contractors just consider rings an added complication particularly considering that you have to route the cables back to the board at both ends. In sprawling bungalows (quite common here) it's much easier not to have to do that!

[This message has been edited by djk (edited 10-21-2003).]

Yes, domestic panels here are almost always just a single row of fuses or breakers.

Have a look at Consumer units here for the types typically used in a modern installation.

Sven,

NEC (2002 edition) 110.14(A) has a reference to more than one wire per terminal:

110.3(B) states:

Put those two together, and I reckon that's covered the issue. Maybe one of our NEC experts can confirm or add something to this.

take only one terminal of tne neutral bar, and you've got the terminals we used for junction boxes before the wagos came. when you use only wires of the same diameter, there is no problem fixing more of them together in one terminal.

updates:

i read in between that a VDE rule is: every neutral conductor must be connected extra on a panel's neutral bar.

and, i've seen 3 phase cables being installed at the company i work with the third phase gray. so looks like this is sure coming up.

Paul Cornwall said:


Did the update do away with the "shaver socket" (two round pin socket with isolation transformer)?

Sometimes you could probably plug a small radio into one of those (with the right adapter) without blowing up the transformer.

How does a person shave or dry their hair? Is it back to using those little screw-in plug bodies like this bad boy?

[img]http://images.lowes.com/product/032664/032664116506.jpg?wid=158&cvt=jpeg[/img]

No, they drag an extension cord from an adjacent room and plug it in there, peferably into an outlet that isn't GFI protected
By the way, we never had the version that only offers a single outlet here, only the one with 2 sockets and light bulb. Usually made of porcelaine and widely used for powering electric irons in the 1930ies and well into the 50ies, then those rapidly died out.

Bathroom thing: sorry but that with the permitted outlets sounds silly to me.

imagine the connector of the extension cord (how is that called? the "mobile" receptacle) falls into the tub.
you cant get the fixed bathroom receptacle to the tub unless you smash the wall... and the cable to your hairdryer is one piece with no water sensitive connections in it.

[This message has been edited by :andy: (edited 10-29-2003).]