skts x 2 earth terminals

[driverman]

Been 2nd fixing today, which i've not done for many years. I've noticed that both Volex 13A twin & single sockets have 2 x earth terminals. Is that now standard? I thought that requirement was only applied to sockets that served a lot of IT equipment. Even years ago i would sleeve the earths separately, but then into one terminal. Is there any electrical reason for the change? Thanks

 

[Deleted member 26818]

There are arguments for both.
Twisting together would allow for continuity of the conductors, if the terminal became loose.
Twisting together restricts the number of conductors that can be terminated.
Twisting together is a pain when it comes to testing.

 

[Tidy Max]

The only conductor twisting i do is when i am installing or building an induction loop!

 

[Guest77]

I cannot see the problem myself, if you connect the CPCs into seperate terminals and one breaks or isn't tight the socket is still protected, if in one terminal then the same as it always has been, who cares, it is no big deal either way on a standard domestic outlet.

 

[Guest77]

Why should you use both terminals when doing a ring main?

Why Not?

 

[Deleted member 26818]

Some sockets have 2 terminals for each of the circuit conductors.
This increases installation times and increases the likelihood of a termination loosening.
If one terminal fails, then yes the conductor is still connected, though using a plug in tester would not show that a conductor had fallen out.

 

[driverman]

I cannot see the problem myself, if you connect the CPCs into seperate terminals and one breaks or isn't tight the socket is still protected, if in one terminal then the same as it always has been, who cares, it is no big deal either way on a standard domestic outlet.

i can't see it making any difference what so ever. However, as not in the game as such I just wondered why the introduction. Surly must be more expensive to produce, therefore there must be a reason why. Could it be an EU instruction?

 

[Risteard]

Presumably it is to enable the socket outlet to be used where there are high protective conductors currents.

Personally I would always use both terminations.

 

[Deleted member 9648]

i can't see it making any difference what so ever. However, as not in the game as such I just wondered why the introduction. Surly must be more expensive to produce, therefore there must be a reason why. Could it be an EU instruction?

EU are not interested in UK sockets....the reason is manufacturers dont have to manufacture both types....cheaper to tool for one only,and the extra cost of the two terminals is sneaked onto us.

 

[SJD]

In fault-finding an RFC with a higher-than-expected value for r2, on at least a couple of occasions it has turned out to be due to relying on the socket internal metalwork.

One end of the RFC into one terminal, the other end of the RFC into the other terminal. Screws done up tight. But the sockets had riveted bits of metal work, not always making good contact. I've seen sockets with the best part of an Ohm measured between the two terminals.

 

[Tidy Max]

I had the exact same issue about 6 months ago. It was a single socket that had been connected up that way causing the issue. I re terminated them and the lowered the value however after reading this thread i was thinking the terminations just may have been a bit crap!

 

[driverman]

Awww now i'm thinking put both earths into one terminal! Which is what I have been doing for years!

 

[Doomed]

No matter what you do it will be wrong somehow.

Especially if your married.

 

[driverman]

No matter what you do it will be wrong somehow.

Especially if your married.

Baffled....although had a few drinks hic

 

[wildgoose]

Decent sockets with double pole switching, will have 2 earthing terminals. The cheaper single pole switched sockets - which I stay away from, normally have just the one earth terminal.

I personally will use both earth terminals on a newly wired sockets only because it looks better. On a refurb/replacement socket, I'll use whichever terminal is best for the existing cable length.

Earthing of the metal knockout boxes in domestic applications, is of course not required providing one of the mounting lugs is fixed.

 

[ayjay]

use tenby sockets
they have very fine terminal threads and don,t loosen

 

[Engineer54]

Well i would personally use one of the socket earth terminals for the rings circuit conductors, and the other for a flying lead to the back box. I don't really care what BS7671 has to say about relying on a face plate fixing screw, i was taught to use flying leads to the back box and see no reason not to continue to do so!!

 

[shanky887614]

Baffled....although had a few drinks hic

nothing rong with that, just got back fron pub myself.

not completely out of it yet, but i need to take extra care wiyh spelling

 

[wildgoose]

Nothing wrong with flying earth leads inside the boxes - I was taught that way back too. However, back in the old days of the 60's & 70's, you really did need flyleads. Limited use of rcd's and no knockout box grommets was common place - how many original socket boxes from this era do you find without any grommets?

 

[Simlec]

There does appear to be a misinterpretation of the requirements for 2 separate CPCs for such circuits.
One conductor run in a ring formation and terminated at separate terminals does not equate to two CPCs.
It needs two separate conductors, each connected to a separate terminal in order to comply.

Im not sure what your saying Spin?
Are you saying the image (for example) in Guidance note 8 page 132 is incorrect!
As it says on page 131 that if the ends of the protective conductor are separately terminated at DB & sockets then Reg 543.7 will be met as shown in image

 

[onions1066]

Hey guys. Haven't been on in a while but is this really what it's come to arguing over how many earth terminals to use in a domestic socket. Does it actually matter. ...........

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