How much of a risk is it not earthing a ceiling light?

[Gees]

I knew that already... What I asked was What is the actual physical diffrence

 

[Gees]

Because 4mm² is the minimum size for an unprotected earth cable.

You are probably right but I cant find this in BS7671? Have you a page number?

 

[holmslaw]

..

 

[Gees]

Because 4mm² is the minimum size for an unprotected earth cable.

You are probably right but I cant find this in BS7671? Have you a page number?

Found it ..................Apologies

 

[holmslaw]

..

 

[dingbat]

No apology necessary, but thanks anyway.

A lot of non-NICEIC contractors believe they have their own set of regs, indeed many in the 'club' think this too, because their work is criticised. But, the NICEIC inspecting engineers always assess work to BS 7671. They may suggest a method of achieving compliance that a contractor thinks is OTT, but invariably that is because the contractor has, often for years, used a non-compliant solution, or an outdated one.

 

[Gees]

I knew that already... What I asked was What is the actual physical diffrence

Class 1 will have an earth terminal class 2 do not have an earth terminal.

Thats a bit obvious but how is the wiring different ( thicker insulation - more of it ?? )

 

[holmslaw]

..

 

[skenk]

A lot of non-NICEIC contractors believe they have their own set of regs, indeed many in the 'club' think this too, because their work is criticised. But, the NICEIC inspecting engineers always assess work to BS 7671. They may suggest a method of achieving compliance that a contractor thinks is OTT, but invariably that is because the contractor has, often for years, used a non-compliant solution, or an outdated one.

So would you agree that NIC inspectors would insist on something like an earth fly-lead to a metal back box, even though the (apparent) consensus on here is that BS7671 requires only a screw/fixed lug?

 

[Monkeh]

I knew that already... What I asked was What is the actual physical diffrence

Class 1 will have an earth terminal class 2 do not have an earth terminal.

Thats a bit obvious but how is the wiring different ( thicker insulation - more of it ?? )

The basic requirement is that no single failure can result in dangerous voltage becoming exposed so that it might cause an electric shock and that this is achieved without relying on an earthed metal casing. This is usually achieved at least in part by having two layers of insulating material surrounding live parts or by using reinforced insulation.

Typically a sturdy plastic case or two layers of insulation.

 

[1john]

A lot of non-NICEIC contractors believe they have their own set of regs, indeed many in the 'club' think this too, because their work is criticised. But, the NICEIC inspecting engineers always assess work to BS 7671. They may suggest a method of achieving compliance that a contractor thinks is OTT, but invariably that is because the contractor has, often for years, used a non-compliant solution, or an outdated one.

So would you agree that NIC inspectors would insist on something like an earth fly-lead to a metal back box, even though the (apparent) consensus on here is that BS7671 requires only a screw/fixed lug?

My inspector wouldn't, they check your work in accordance with BS7671, the niceic do however provide technical data which is in effect their version of the iee guidance notes.

 

[ban-all-sheds]

The blurb just mentions "extra insulation" .... Could this not be retro fitted?

No - it has to be designed into the product - there's nothing you can do to a Class I luminaire to turn it into a Class II one and still get light out of it.

 

[dingbat]

A lot of non-NICEIC contractors believe they have their own set of regs, indeed many in the 'club' think this too, because their work is criticised. But, the NICEIC inspecting engineers always assess work to BS 7671. They may suggest a method of achieving compliance that a contractor thinks is OTT, but invariably that is because the contractor has, often for years, used a non-compliant solution, or an outdated one.

So would you agree that NIC inspectors would insist on something like an earth fly-lead to a metal back box, even though the (apparent) consensus on here is that BS7671 requires only a screw/fixed lug?

No. A NICEIC inspecting engineer should never insist on anything not required by the regulations. This back-box malarkey is one particular non-requirement that they are all very much aware of. The consensus to which you refer is nothing to do with this forum, by the way, but that of the IET national committee (See Guidance Note 1)

But the NICEIC use 'associates' to carry out annual inspections of Domestic Installers. These are usually other contractors, albeit with a high level of knowledge, who may bring with them baggage of this kind.

However, an NICEIC-registered electrician carrying out a PIR is as fallible as a NAPIT electrician, an ECA electrician or any other and may well dream up non-existent requirements. In fact, I have yet to see a correctly compiled PIR, largely for this reason.

 

[1john]

TBH Dingbat, until the regs are clear cut (never) there will always be differences in opinions and incorrect departures noted on PIR's, it is a book full of 'shoulds' ! There are some members in here that truely believe that the regulation instigating the provision for a main switch, ie single point of isolation for an entire installation, is infact a regulation for shower oull cords to be sighted inside bathrooms!

 

[dingbat]

TBH Dingbat, until the regs are clear cut (never) there will always be differences in opinions and incorrect departures noted on PIR's, it is a book full of 'shoulds' ! There are some members in here that truely believe that the regulation instigating the provision for a main switch, ie single point of isolation for an entire installation, is infact a regulation for shower oull cords to be sighted inside bathrooms!

What almost everybody doesn't get is that the Regulations are not only clear-cut, they are almost absolutely so.

They are not, nor have they been for many decades, a practical installation guide, but instead are a series of requirements that must be achieved. How those requirements are achieved is up to the individual, but standardised solutions do exist; the problem is that most (I'd say almost 100%) electricians do not understand how to read the Regulations and imagine instead that those solutions are in fact mandatory.

Given that the Regulations are written to be read by the technically competent and the demonstrable reading age of the electricians I get in my classes every week is around twelve (I'm deadly serious - it's about the reading competence of the average bloke in the street) it's no surprise that sparks simply do not 'get' the Regs.