Metal back boxes and cpc

[riveralt]

As a matter of course I have always connected the metal back box earth lug to the socket earthing terminal.

However, to me, it appears that the size of todays socket terminals are getting smaller and its getting increaingly difficult to correctly terminate four cpc's in the one earthing terminal. (Ring main, spur and fly lead equates to 6mm2 of conductor into one terminal)

Aside from purchasing those sockets that have two cpc terminals, is it within the regs to run one of the cpc's (say the spur) to the metal back box earth lug - continuity would be maintained because of fly lead. Thus there would be a little more space in the earth socket terminal to get a good tight fit for the three remaining cables.

 

[GaryMo]

There's no problem at all in doing that though you also shouldn't have a problem connecting 4 x 1.5mm2 cpc's in a socket earth terminal either.

 

[Spark123]

We were always told not to do it that way as apprentices. The back box earthing lug is usually pretty poo anyway.
Try using a half decent brand socket such as MK

 

[1john]

if you have a fixed lug then you dont need to earth the back box, if you dont though you must.

 

[properleckie]

Devils advocate,,,

Where in IEE regs. [not NICCY version] does it require 'pig-tail' to box in twin+cpc wiring?

Only mention AFAIK of use of pig tail is when using conduit, swa, pyro as cpc as per reg. 543.2.7 and you are bringing earth FROM box TO outlet, not the other way.

sorry for those who don't like reg # being used but it's needed this time,[page 131 in current version].

 

[disinfo]

Should the regs be put before good practice?

 

[properleckie]

Is it 'good practice' to cram another unnecessary, pointless, bit of wire in an already small space?
what does it achieve?

 

[holmslaw]

..

 

[sparkwright]

Is it 'good practice' to cram another unnecessary, pointless, bit of wire in an already small space?
what does it achieve?

it ensures both the accessory and the back box are earthed even if the faceplate is loosened off for some reason.

 

[GaryMo]

I personally dislike seeing backboxes without an earth link, in fact we had a guy working with us for a while who did a second fix without installing earth links.
He went back to fit them after being told he was a rough ar*e!

I guess it's just the way you're 'brought up'

 

[properleckie]

Holmslaw/sparkwright you miss the point!

The accessory/front plate is earthed by the CPC in the cable, under EAW regs nobody such as a decorator should be removing/loosening a live outlet or switch plate.

 

[holmslaw]

..

 

[properleckie]

and why would an unearthed back box cause a 'shock' pray tell?

yup!.... & yup! should be removed from the gene pool forthwith!

but the decorators scraper is going to do that for us!

Holmslaw how is the 'plate ' unearthed'? who is talking b0ll0x?

In 43 QUALIFIED years in the trade I have never heard of anyone getting a shock from a back box!

 

[holmslaw]

..

 

[properleckie]

close; apprenticed 1963-1968

1966 first C&G exam, still sitting the blooming things at 62 years old!

2391-10 next week, last one ever!

Can't take much more B-S, roll on retirement, glad i'm not just starting out! Feel sorry for those who are.
Shouldn't moan really never had a day out of work & I love what I do apart from government interference.