Loft Lighting Ask questions and find answers to many subjects relating to electrics and electrical work

[Dr.Robotnik]

Dear All,

I am new to the forum and hope my question hasn't been gone over too many times already.

I have provisionally laid some flooring in my loft by torch light but would ideally like to have a proper light up there to see what I am doing.

However I am confused about Part P (probably no surprise there). Basically I already have all the bits I require and was looking for some guidance on what I'm allowed to do these days.

Is a loft a "special location"?

Is an additional light switch and bulb socket a "new circuit"?

If not then I think I understand I am allowed to wire (1.5mm wire) in a light switch and a ceiling rose off an existing ceiling rose correct?

Thank you for any help and assistance.

[ericmark]

Special locations are bathroom, kitchen and outside plus the consumer unit. So seems OK as far as that goes.

New circuit under BS7671:2008 is adding a fuse or MCB (protective device) but under Part P it seems only when taken from the consumer unit is it considered a new circuit so OK as far as that goes.

However as I have said in another post for any DIY man to inspect and test his work which will require meters costing £750 to buy and £75 to hire is near impossible to expect. So although permitted by Part P it is unlikely you can do the work and comply with regulations.

[Dr.Robotnik]

However as I have said in another post for any DIY man to inspect and test his work which will require meters costing £750 to buy and £75 to hire is near impossible to expect. So although permitted by Part P it is unlikely you can do the work and comply with regulations.

Oh, so you are saying this comes under notifiable work? Strange I thought I'd read it wasn't. I'll have to dig through my research from yesterday as it's all at home now though.

Is there anywhere to get the conclusive legal answer as I'd heard planning authority's don't know the regs properly yet?

Also am I a competent person having done this before and studied engineering or do I have to register?

[Dr.Robotnik]

Not notifiable and not inspectable according to the NICEIC.

Cheers all.

[kbrownie]

Dr.Robotnik,
It is non-notifiable work, but regardless of that, it still needs to comply to part p of the building regulation, as does all electrical work in the home.
The type of work you wish to carry our is know as minor work, as you are adding on or extending and existing circuit.
A minor works certificate should be issued for this type of work (but often is not)
To complete a minor works cert there are some essential test to be carried out. To prove the work done is safe.
There is nothing in law saying you can not do this, but you will need the correct equipment to carry the test out.
Also you are not a competent person, unless you have the skill, knowledge and experience to carry this out.
As an electrician, to prove competance, we need to be accessed on the work we do normally by a scheme provider.
The cable you use should be the same CSA as the cable already installed on the circuit you are adding to.
Hope this helps, you understand a little bit better.
Part P is a regulation that must be complied to, regardless of notification. Notification is informing building controls you intend to have work done that will comply to Part P and any other relevant standards to assure your installation is safe.

[ericmark]

There is Part P which is Law and there are two categories notifiable and non notifiable your work falls into latter. But to comply with Part P you also need to comply with BS7671.

BS7671:2008 also know as 17th Edition wiring regulations requires you to test any work completed and to write down the results. This already covered.

It also requires you to have the skill required there are 4 levels of skill.
1) Ordinary person. A person who is neither a skilled person nor an instructed person.
2) Instructed person. A person adequately advised or supervised by skilled persons to enable him/her to avoid dangers which electricity may create.
3) Skilled person. A person with technical knowledge or sufficient experience to enable him/her to avoid dangers which electricity may create.
4) Competent person. A person who possesses sufficient technical knowledge, relevant practical skills and experience for the nature of the electrical work undertaken and is able at all times to prevent danger and, where appropriate, injury to him/herself and others.

As you can see it does not require a qualification as such but to sign the certificate you need to fall into group 3) or 4) and really it needs to be the highest level number 4).

On this forum there is a problem as most people who ask questions will not fall in to 3) or 4) so where asked "Can I" in the main the answer is no. However we know they will attempt the work and to get them to do it as safe as possible is our aim.

However to say yes you can is of course wrong as we know all too well people will not inspect and test their work and without the testing it is likely the earths will be missing, the volt drop will be too great, and the fault current will be too low to open the automatic protection devices within the required time. And each alteration is likely to miss any previous mistakes because of lack of testing.

Most accidents are not caused by a single fault. They are caused because a number of faults have all compounded. It is unlikely that a single alteration on it's own will therefore cause a danger but it is the combination of loads of little jobs which cause the problem.

However if something does go wrong the last person to work on the system is held responsible for any faults not reported in writing. All health and safety stuff must be in writing verbal reporting is not enough. Hence why the minor works certificate is made out. For the guy doing the work it shows he has taken all reasonable precautions and it was OK when he left and is a get out for him. And for the house owner it shows the readings so next time one can see if the wiring is degrading.

So adding to a system first job is the measure the prospective short circuit current and or loop impedances which are really the same but one measured in amps the other in ohms and from those readings we will know if the system will stand anything being added to it. However unlike insulation tests which have a one meg ohm pass level for near all circuits the pass level is dependent on the protective device.

So with a RCD a ELI of 200 ohm will pass but without an RCD then for sockets 1.44 ohm (B32 MCB) and for lights 7.67 ohm (B6 MCB) ohms law is used to convert these to amps for the Line / Neutral reading so 160A for B32 MCB and 30A for a B6 MCB these figures ensure that with a fault the magnetic part of the MCB works which will trip within 0.1 seconds. If these figures are exceeded then with for example a 6A MCB at 10A it will take nearly 10 minutes before it trips which is enough time for a fire to start and I would certainly not want to be receiving a shock for 10 minutes!

In the old days of fuses the point where enough current flowed was not so cut and dried but this the modern MCB we have to ensure with a short circuit either Line to Earth or Line to Neutral the magnetic part will work. With a type C MCB looking at 10 times rather than 5 times so 320A for C32 MCB and 60A for C6 MCB and were combined with an RCD (RCBO) the C type is common. And the D type is 20 times only used for motor control normally but have seen them in consumer units.

So I am not saying that what you are doing on it's own is dangerous but 5 years passes and you doing another job knock a nail through the cable and that's when the problem arises. As I have said most accidents are caused by a combination of faults not just one.

What you need to do is a risk assessment. Is the saving of money doing DIY work on electrics worth the risk to you and family and property remembering that your insurance may not cover if it is found the work you did does not comply.

Only you can answer that question. If it were me (And I did not own the loop impedance, High and low ohmmeter, plus RCD tester) I would do the work then I would pay for a periodic inspection report which should highlight any mistakes. However I do have the set of three meters needed to fully test my work. But at £75 to hire although have seen odd place as low as £25 likely cheaper to get someone to inspect and test than to hire the meter. Also then your no longer the last person to work on the system.

[Dr.Robotnik]

Thank you for your answers guys.

Just to clarify, the NICEIC, is happy for me to undertake this work. I am an aerospace engineer. I have access to testing equipment, have done this sort of thing before and have a friend who is an electrician to double check the work.

However, just to answer some of the points you raise.

The NICEIC did not mention that I would require a minor works certficate.

To quote Part P, page 12.

Inspection and testing of Non-notifiable work.
1.30 Non-notifiable electrical installation work must also be carried out in accordance with requirements of BS7671:2008 or an equivalent standard. However it is not necessary for the work to be checked by a buiklding control body or alternatively varried out by an installer registered with a Part P competent person self-certfuication scheme.

Also Re: schemes: I thought Part P, just says it reccomends you join a scheme, not you have to?

Thank you for the note on the CSA of cables I will double check that the new addition uses the exact same cable.

Re: BS7671:2008 regs;

I have downloaded and intend to fill in Form 5 Minor electrical installation works certficate.

Cheers for the mathematical example too, gave me a good little pointer. :wink:

I will do the work and a few other little odds and sods and then get a full system test in April. Seems fair enough to me.

I'll post what I am actually going to do in a bit so you can say stop if necessary.

Cheers

[Dr.Robotnik]

So adding to a system first job is the measure the prospective short circuit current and or loop impedances which are really the same but one measured in amps the other in ohms and from those readings we will know if the system will stand anything being added to it. However unlike insulation tests which have a one meg ohm pass level for near all circuits the pass level is dependent on the protective device.

So with a RCD a ELI of 200 ohm will pass but without an RCD then for sockets 1.44 ohm (B32 MCB) and for lights 7.67 ohm (B6 MCB) ohms law is used to convert these to amps for the Line / Neutral reading so 160A for B32 MCB and 30A for a B6 MCB these figures ensure that with a fault the magnetic part of the MCB works which will trip within 0.1 seconds. If these figures are exceeded then with for example a 6A MCB at 10A it will take nearly 10 minutes before it trips which is enough time for a fire to start and I would certainly not want to be receiving a shock for 10 minutes!

In the old days of fuses the point where enough current flowed was not so cut and dried but this the modern MCB we have to ensure with a short circuit either Line to Earth or Line to Neutral the magnetic part will work. With a type C MCB looking at 10 times rather than 5 times so 320A for C32 MCB and 60A for C6 MCB and were combined with an RCD (RCBO) the C type is common. And the D type is 20 times only used for motor control normally but have seen them in consumer units.

BTW my current ring circuit has two ceiling roses with a single 85W bulb each on them at the moment, protected by a B6 MCB.

It's not very likely to have a problematic circuit current or loop impedance is it?

It definitely seems a heck of a lot of trouble to add one light bulb... :lol:

[kbrownie]

Non notifiable work does not to be inspected by BC or verrified by an electrician of any type registered or not.
You can do it, without them if you wish.
But BS7871:2008
States; where minor electrical installation work is done (additions and alterations existing circuits) that a certificate of Minor Works or an EIC shall be issued.
This is also something you can do providing you have the knowledge and the test equipment.

[sparx]

Just to add my 2 pennyworth, KB sums it up nicely in his last comment,
I would just add that the IET write the regs NOT the bl##dy niceic, who are only one of the many operators of part pants schemes/scams!
Frequently the nic voice their opinion of what they would like the regs to say rather than what they do say.
You can do this work yourself, it does not need reporting to anyone , the only time it will be a problem is if you attempt to sell the property or an insurence co.asks the same question as conveyensers/ solicitors.
ie
" Has any electrical work been done in the last # years and is there supporting documentation?"

[ericmark]

[quote="Dr.Robotnik"]

BTW my current ring circuit has two ceiling roses with a single 85W bulb each on them at the moment, protected by a B6 MCB.

It's not very likely to have a problematic circuit current or loop impedance is it?

It definitely seems a heck of a lot of trouble to add one light bulb... :lol:[/quote]
Why would anyone use a ring circuit with two ceiling roses and a B6 MCB? Allowed a Zs of 7.67 ohms unlikely to exceed that unless there is a bad connection some where. However unless you test how can you be sure no bad connection?

[BLAKEY1963]

ROBOTNIK
Complete your minor works certificate for the work that you
intend to do.

BLAKEY1963