Earthing Metallic Back Boxes In Houses

[brian2010]

Do metallic back boxes still need earthing?? As I understand the regs and risk assessment ect I still do, but I am finding lately in debates ect that some so called sparks are telling me that it's not compulsory now to earth back boxes in a domestic installation have NICEIC changed this'?????????? I've been through the regs along with risk assessments and each time I come to the conclusion back boxes have to be earthed??????? Pls help fellow Sparks TY

 

[Zeespark]

Brian, the NIC like to think that they write and control the regs - they do NOT, there is nothing in BS7671 to say you must, but I personally would, especially it install non PVC wiring accessories. :innocent

Andy Guinness

 

[Barx]

I was always under the impression that if the back box has at least 1 fixed lug then it is not needed. I still always do it out of principle and good practice.

 

[Blue Duck]

I'm with the owls

Nic talk bolox.

 

[m4tty]

+1 to the above

 

[Doc Hudson]

Do metallic back boxes still need earthing?? As I understand the regs and risk assessment ect I still do, but I am finding lately in debates ect that some so called sparks are telling me that it's not compulsory now to earth back boxes in a domestic installation have NICEIC changed this'?????????? I've been through the regs along with risk assessments and each time I come to the conclusion back boxes have to be earthed??????? Pls help fellow Sparks TY

The requirements for earthing and bonding of exposed and extraneous conductive parts in the current regs remains the same as it did previously. The metal back-box issue is one area where for the sake of a short length of wire and a few seconds extra terminating it is not to much hassle to fit if it worries you. On the other hand if you take the consideration that bathroom bonding may be omitted if full RCD protection is in place as per 701.415.2, then as the potential dangers in a bathroom are far higher than the risk of shock from the small exposed metal screws around a socket. Then as most domestic sockets & lights now also have to be RCD protected, by same reasoning the metal back-boxes probably don't need any earth connection. At the end of the day I think it is down to your judgment call for that particular installation. It is not hard to do it, nor is it a major hazard if you don't. if RCD's are in place.

Doc H.

 

[SLIPSHOD & SLAPDASH]

The 'flylead' debate has been around years. The confusion came from when the  regs said ( and  have always said) if the containment is used as the cpc you have to have a flylead. Nowadays a separate earth conductor is nearly  always used so it may not be necessary. The general interpretation is if there is at least one fixed lug on the box a flylead is not needed. 

 I put up a pic only a month or so ago that the current Toolstation sockets have no link from the socket  screwholes to the earth terminal, so that needs a link . I also have seen many cheap sockets where only one screwhole has the link to the earth terminal so that needs a link if this does not line up with the fixed lug.

I always fit a link.

 

[brian2010]

Cheers ALL!

My conclusion!!! Design,2391,Regs,Building regs and risk assessment all taken into account!

Back boxes need earthing!

Reason!!

Faults

If a competent person or even a DIY person were to remove a accessorie and recived an electic shock causing injury or death as a result of investigating the fault, if there were no earthing to the back boxes then the ELECTRICIAN WHO SIGNED OF THE WORK is FCUKED!!!! As the regs state BASICALLY HAVE U DONE EVERYTHING TO PREVENT RISK OF ELECTRICUTION!!!!!!! By not earthing back boxes then you have not done everything practable within your power to reduce electrical shock! This was taught to myself years ago as an apprentice by my bosses and in my apprenticeship college and regs course and 2391 course and design course along with IOSH (risk assessment) and still today I meet all good electrical boss's and supervisors who I ask this too and there reply is the same as my answer ALL METTALIC BACK BOXES NEED EARTING DUE TO THE ABOVE REASON!!!!!! N

Any response regarding this??

 

[Doc Hudson]

Just to throw in a counter point to the above post. What about EAWR 1989, Regulation 14, which basically states that no person shall do any work activity on or near any conductors unless it is completely unreasonable in all circumstances for the circuit to be made dead. So what is your justification for working on an accessory that is still live when it is not difficult to isolate the circuit before you open up the accessory to do your fault finding, maintenance or alteration work? Remember EAWR is statutory, BS7671 is not. Irrespective of if a back box is earthed or not, if you open a live accessory there is just as much danger of direct contact with a live conductor anyway.

Doc H.

 

[NozSpark]

+1 Doc

 

[Sidewinder]

Cheers ALL!

My conclusion!!! Design,2391,Regs,Building regs and risk assessment all taken into account!

Back boxes need earthing!

Reason!!

Faults

If a competent person or even a DIY person were to remove a accessorie and recived an electic shock causing injury or death as a result of investigating the fault, if there were no earthing to the back boxes then the ELECTRICIAN WHO SIGNED OF THE WORK is FCUKED!!!! As the regs state BASICALLY HAVE U DONE EVERYTHING TO PREVENT RISK OF ELECTRICUTION!!!!!!! By not earthing back boxes then you have not done everything practable within your power to reduce electrical shock! This was taught to myself years ago as an apprentice by my bosses and in my apprenticeship college and regs course and 2391 course and design course along with IOSH (risk assessment) and still today I meet all good electrical boss's and supervisors who I ask this too and there reply is the same as my answer ALL METTALIC BACK BOXES NEED EARTING DUE TO THE ABOVE REASON!!!!!! N

Any response regarding this??

The person taking the accessory off & not undertaking safe working procedures (safe isolation) then they get what they deserve.

Noting that if they were employed, they would be in breach of EAWR89 Reg 14 as has already been said.

Also, anyone removing an accessory without isolating it, would also be in breach currently accepted working practices within the industry.

There is no guarantee that an earth connection to the back box would prevent the death, it depends on the failure mode, and the mode of electrocution.

There is no definitive requirement to connect a metallic flush back box to the earthing of the installation, unless the containment is being used as the cpc, which contrary to popular beliefs is still acceptable, as is using the swa of an armoured as the cpc for a circuit (& a bonding conductor, except for a few limited situations for both).

 

[kerching]

So.......someone elects to work live...

Takes front off socket

Live side comes out of back of socket and starts arcing and frapping about

What does that "person" do?....shove it back and pray?

Leave dangling like the last turkey in the window whilst they scurry off and isolate?

Wish they had isolated in the first place?

Or, now here is a thought, isolate it in the first place and live to see another Xmas Special with Rachel Riley dressed as a ......sorry, rambling again

 

[OnOff]

So.......someone elects to work live...

Takes front off socket

Live side comes out of back of socket and starts arcing and frapping about

What does that "person" do?....shove it back and pray?

Leave dangling like the last turkey in the window whilst they scurry off and isolate?

Wish they had isolated in the first place?

Or, now here is a thought, isolate it in the first place and live to see another Xmas Special with Rachel Riley dressed as a ......sorry, rambling again

Sorry...........all I can think about now is Rachel Riley's back box..........

 

[kerching]

Sorry...........all I can think about now is Rachel Riley's back box..........

Mmmmmmmmmmmmmmmmmmmmmmmm

Just a thought.....is the act of "bonding" classed as bondage?

RR ,Bonding, Santa Outfit...........wonder if she does a calendar?

Just .......praying

 

[ProDave]

Can I throw another one into the melting pot.

Metal light switch, where back box is earthed but switch plate is not.

Same argument applies.  With the switch in place, it's front plate will be earthed trough the screws.  With the front plate removed, well you should have isolated first shouldn't you.

Discuss.

(I come across this frequently when the home owner has changed the light switches and upon removing the plastic one, they only find 2 wires, so swap these over to the new switch. They don't notice or don't care that there's an earth connected to the back box that really ought to be connected to the earth terminal on the light switch)

 

[Sidewinder]

Down to the ***** modifying being incompetent.

Nothing anyone who has been there before can do about it.

Not our job to have a crystal ball and consider all potential modifications.

 

[NozSpark]

Not following manufacturers instructions

Nearly all that I have seen either come with "This switch must be earthed" in the leaflet or on a sticker next to the earth terminal

 

[brian2010]

Remember it's a fault!!!!! And if back box is not earthed !!! And we follow all SAFE ISOLATION PROCEDURES and get a belt/electric shock as remember it's a fault, back boxes not earthed regardless of weather we would or wouldn't get shock if it was or not, if. Back boxes are not earthed then we have not done everything practicable within our power to reduce electic shock!!!!

 

[Sharpend]

Am missing something Brian?

So the back box is earthed via the screw when in normal operation, so under fault condition as you call it in normal operation then wouldn't you get a L-E short which would cause the OCPD device to trip?

And as others have stated any good sensible person would follow safe isolation prior to removing faceplate, so where's the risk?

Are you trying to achieve a 100%, all eventualities ***** proof system? If so good luck as the idiots are far more clever than you or I. ?

 

[ProDave]

+1

Make something ***** proof, and someone will come up with a better *****.