Poll - Ring final circuits with high integrity earthing

[EFLImpudence]

That's what I thought so there is an element of shock prevention as well.

So, if one of the connections comes away, a loose end could present a risk no matter how many cpcs there were.

It would be better still, then, if, as well as the separate connections at each socket, the two ends of the cpc were also connected together permanently by a joined link.

 

[JohnW2]

That's what I thought so there is an element of shock prevention as well.

I don't know about "an element of" that. I think it is all about shock prevention.

So, if one of the connections comes away, a loose end could present a risk no matter how many cpcs there were.

No, not if there is CPC 'redundancy' (i.e. more than one path to earth, connected to a different terminals), as in a ring - that's the whole point.

It would be better still, then, if, as well as the separate connections at each socket, the two ends of the cpc were also connected together permanently by a joined link.

Sure, but that would not be easy to implement, without Y-crimps (or something like it), or 'yet more' screwed connections.

Kind Regards, John

 

[EFLImpudence]

So, if one of the connections comes away, a loose end could present a risk no matter how many cpcs there were.

No, not if there is CPC 'redundancy' (i.e. more than one path to earth, connected to a different terminals), as in a ring - that's the whole point.

Yes, silly me - forgetting about all the other connections.

It would be better still, then, if, as well as the separate connections at each socket, the two ends of the cpc were also connected together permanently by a joined link.

Sure, but that would not be easy to implement, without Y-crimps (or something like it), or 'yet more' screwed connections.

Twisting?

 

[deadshort]

High integrity Ring Circuits , 6 terminal sockets (made by RRP for CEF in the 80's ) fantastic idea, yes, until you have a spur !
I think this will become a reality when we reach the 18th

DS

 

[JohnW2]

No, not if there is CPC 'redundancy' (i.e. more than one path to earth, connected to a different terminals), as in a ring - that's the whole point.

Yes, silly me - forgetting about all the other connections.

It's very easy to forget things in this discussion

Sure, but that would not be easy to implement, without Y-crimps (or something like it), or 'yet more' screwed connections.

Twisting?

I suppose that would be 'a lot better than nothing', provided that it did not in any way compromise the connections, or the maintenance of the connections, to the 'protective conductors proper'.

Kind Regards, John

 

[JohnW2]

High integrity Ring Circuits , 6 terminal sockets (made by RRP for CEF in the 80's ) ... S

Do you mean 6 'earth' terminals? (even BAS only needs 4!)

Kind Regards, John

 

[Iggifer]

I'm assuming 2 each of LNE

 

[JohnW2]

I'm assuming 2 each of LNE

That was my first reaction - but that's what most sockets I buy today have - but it sounded as if DS was talking about something 'special'!

Kind Regards, John

 

[deadshort]

I'm assuming 2 each of LNE

yip.

DS

 

[Iggifer]

That was my first reaction - but that's what most sockets I buy today have - but it sounded as if DS was talking about something 'special'!

OOI what sockets do you buy? I only really ever use 3 brands, and they all have one L+N and 2 Earth (of which, I only ever use one)

 

[333rocky333]

High integrity Ring Circuits , 6 terminal sockets (made by RRP for CEF in the 80's ) fantastic idea, yes, until you have a spur !
I think this will become a reality when we reach the 18th

DS

with the fire brigade blaming screw terminals for fires, I reckon push in terminals will be the way forward

The HI versions having 5 earth terminals

 

[JohnW2]

That was my first reaction - but that's what most sockets I buy today have - but it sounded as if DS was talking about something 'special'!

OOI what sockets do you buy? I only really ever use 3 brands, and they all have one L+N and 2 Earth (of which, I only ever use one)

Oh sorry - I didn't read, think or write carefully enough! What I should have said was that most sockets I buy have 2 earth terminals (since that's what's relevant to this discussion) - but, as you say, they only have one L and one N. It's years since I saw one of these offered for sale (although I still have a few tucked away):

Untitled

• JohnW2
• 29 Oct 2011
• 6

However, although they're nice to install, I'm not so sure about them safety-wise - at least in a ring final. With a ring final, if one of the L's or N's come's adrift, the user will be none the wiser (everything will still 'work' - unless the 'adrift conductor' touches something it shouldn't!), but the circuit's cable could get overloaded.

Kind Regards, John

 

[Iggifer]

with the fire brigade blaming screw terminals for fires, I reckon push in terminals will be the way forward

It wouldn't surprise me, lots of light fittings already have them, I assume there is a reason nobody already makes them.

 

[Iggifer]

However, although they're nice to install, I'm not so sure about them safety-wise - at least in a ring final. With a ring final, if one of the L's or N's come's adrift, the user will be none the wiser (everything will still 'work' - unless the 'adrift conductor' touches something it shouldn't!), but the circuit's cable could get overloaded

That's how I feel about ring finals regardless of how they're terminated in the socket outlets

 

[JohnW2]

However, although they're nice to install, I'm not so sure about them safety-wise - at least in a ring final. With a ring final, if one of the L's or N's come's adrift, the user will be none the wiser (everything will still 'work' - unless the 'adrift conductor' touches something it shouldn't!), but the circuit's cable could get overloaded

That's how I feel about ring finals regardless of how they're terminated in the socket outlets

Yes, I realise that is one of the downsides of ring finals. However, if one is going to have them, then those sockets with 2xLand 2xN terminals must increase the chances of a break in the L or N ring going unnoticed - so (unless there are compensating factors, which there might be) they must be, statistically speaking, 'less safe' than those with only one L and one N terminal (particularly if the two conductors are twisted together ).

Having said that, I seriously doubt whether a cable with a CCC of 20A would come to any harm, let alone cause a fire, if it were carrying 32A continuously (which is not going to happen in practice, anyway) - and if, as is more common, the cable has a CCC of 27A, then an 'overload' of 32A clearly isn't going to result in any catastrophes.

Kind Regards, John