Electrics Upgrade Advice

[JohnW2]

Time and relative dimensions in space in space may allow you to see into 2103 but for most of us we have to limit it to 2014.

Ah! (now corrected!). Mind you, I wouldn't say that your posts are famous for never containing typos - even if you do have an excuse!

I have fitted RCD's and found they don't comply. I have simply slackened off the terminals and tightened again and on re-test everything has passed. There is only one way to know if what you have installed is safe and that is to test and inspect and this is where the whole idea of DIY fails.

Quite so. But so long as the concept of DIY is allowed, I don't think we really have much choice but to adopt some pragmatism. One cannot defend the absence of proper inspection and testing, but it is silly to pretend that it always happens.

Forget Part P and BS7671 ...

I certainly wouldn't say that. Part P ('the law') is merely one sentence which says that reasonable steps should be taken with electrical work to minimise the risk of injury to persons or fire. Anyone prepared to 'forget' or ignore that should not be doing electrical work! Similarly, BS7671 affords a very good guide to what one should do to avoid one's work creating dangers, even if it is not always followed strictly 'to the letter'.

Kind Regards, John

 

[mysearch]

If you undertook any notifiable work yourself, you would have to notify it, and pay the appropriate fee. If a registered self-certifying electrician does such work, (s)he does the notification, at minimal cost.

John, it is my (limited) understanding that your summary above highlights the main issue to the DIYer/homeowner, i.e. notification of work to local authority. As far as the questions raised in this thread, the link below suggests that the fitting of a new CU and/or new circuits requires notification. Irrespective of the competency of the DIYer it seems that costs are incurred by the DIYER to get the appropriate paperwork, such that there may not be much difference in costs either way.

http://www.electricalsafetyfirst.org.uk/guides-and-advice/building-regulations/england/

However, in my case, I was possibly hoping that I might be able to carry out a lot of the installation of the new wiring for the kitchen and utility using the old fuse box, then get a qualified electrician to fit the CU+RCDs+MCBs plus connect and test all new circuits before doing the necessarily notification for me. Is this possible, i.e. would an electrician agree to this?

Even for a DIYer who is competent to design and undertake electrical work (whether notifiable or not), the main issue usually relates to the testing which should be undertaken, since many/most DIYers do not have the equipment and/or knowledge to undertake the required testing.

In terms of test equipment, I have the usual type of multimeter and socket tester. Is there anything else in terms of test equipment that a DIYer might reasonably consider?

 

[ban-all-sheds]

I realise that build regs now restrict the DIYer from certain jobs

Only the screw-up ones.

As long as you don't screw up you can do anything you like.

 

[xr4x4]

Shouldn't metal capping be earthed?

 

[securespark]

As an aside, who did Elite Electrical's website? Or are they Electrical Elite?

Lots of typo's and errors.

Needs sorting to make it look professional.

 

[ban-all-sheds]

Shouldn't metal capping be earthed?

No

 

[ban-all-sheds]

I was possibly hoping that I might be able to carry out a lot of the installation of the new wiring for the kitchen and utility using the old fuse box, then get a qualified electrician to fit the CU+RCDs+MCBs plus connect and test all new circuits before doing the necessarily notification for me. Is this possible, i.e. would an electrician agree to this?

You might find one, but you'd have to agree everything in advance.

You will not find one prepared to sign a declaration to say he designed and installed the circuits if you present him with your fait accomplis.

In terms of test equipment, I have the usual type of multimeter and socket tester. Is there anything else in terms of test equipment that a DIYer might reasonably consider?

http://www.ebay.co.uk/sch/i.html?(i...ce","fault+loop")+(tester,meter)&_sacat=12576

 

[JohnW2]

John, it is my (limited) understanding that your summary above highlights the main issue to the DIYer/homeowner, i.e. notification of work to local authority. As far as the questions raised in this thread, the link below suggests that the fitting of a new CU and/or new circuits requires notification. Irrespective of the competency of the DIYer it seems that costs are incurred by the DIYER to get the appropriate paperwork, such that there may not be much difference in costs either way.

You didn't really need that link - that's what I told you a few posts back!! - since April 2013, just about the only things which are still notifiable (in England) are 'replacement of CU' (their wording, but I presume they intended it to include installing one when there was none to replace!), installing 'new circuits' (and the meaning of that is open to debate) and certain work in the specified 'zones' of bathrooms (and in other 'special locations', like saunas etc.). However, as you say, if the DIYer really is competent and adequately equipped, then the cost of notification is one of the main issues. It certainly means that DIY would be crazy for small jobs - since, in some parts of the country, it can cost £300 or more to notify.

However, in my case, I was possibly hoping that I might be able to carry out a lot of the installation of the new wiring for the kitchen and utility using the old fuse box, then get a qualified electrician to fit the CU+RCDs+MCBs plus connect and test all new circuits before doing the necessarily notification for me. Is this possible, i.e. would an electrician agree to this?

You would have to discuss and negotiate that with the electrician involved. Some might possibly agree to that, but they would presumably want to be involved from the very start (before you did anything), so that they could be part of the design process and 'supervise' whatever parts of the work you did.

In terms of test equipment, I have the usual type of multimeter and socket tester. Is there anything else in terms of test equipment that a DIYer might reasonably consider?

To properly undertake the required tests, you would need kit which costs in the region of £400 - £800 (and, obviously, the knowledge to use it and interpret the results). The main things you can't do with what you've got are measure insulation resistance at high voltage, accurately measure very low resistances, measure 'earth fault loop resistance' and test the operating times and currents of RCDs. Although one can get separate standalone testers for all those things, many/most electricians use 'Multifunction Testers' (MFTs) which do all those things.

Kind Regards, John

 

[ban-all-sheds]

... kit which costs in the region of £400 - £800 ...

http://www.ebay.co.uk/itm/Megger-CM..._Measurement_Equipment_ET&hash=item41867ba140

http://www.ebay.co.uk/itm/Robin-Dig..._Measurement_Equipment_ET&hash=item2a433b1462

http://www.ebay.co.uk/itm/Robin-com..._Measurement_Equipment_ET&hash=item2340692fcb

http://www.ebay.co.uk/itm/Metrel-MI..._Measurement_Equipment_ET&hash=item462749a811

http://www.ebay.co.uk/itm/ROBIN-TES..._Measurement_Equipment_ET&hash=item3f3c62b2c4

http://www.ebay.co.uk/itm/Robin-17t..._Measurement_Equipment_ET&hash=item3a95ec5513

http://www.ebay.co.uk/itm/METREL-IN...005&prg=9173&rk=3&rkt=6&sd=111456416657&rt=nc

http://www.ebay.co.uk/itm/Metrel-Mu...005&prg=9173&rk=1&rkt=6&sd=261585832884&rt=nc

http://www.ebay.co.uk/itm/Metrel-In..._Measurement_Equipment_ET&hash=item3a968dae77

http://www.ebay.co.uk/itm/JOB-LOT-1..._Measurement_Equipment_ET&hash=item3ce6f97f8a

http://www.ebay.co.uk/itm/METREL-EU..._Measurement_Equipment_ET&hash=item5d4fb23ed0

http://www.ebay.co.uk/itm/Metrel-Ea...860?pt=LH_DefaultDomain_3&hash=item2ed6630f74

 

[mysearch]

Just wanted to say thanks for all the knowledgeable advice - its been an education plus thanks to DIYnot.com for providing the website. I think I now have a pretty good idea of what I can do for myself and what I need to sort out with a professional electrician.

P.S. thanks for all the links regarding test equipment, but you were right about costs and expertise needed to do the tests surrounding the installation of RCDs.

 

[JohnW2]

... kit which costs in the region of £400 - £800 ...

<a long list of eBay listings for used MFTs etc., most with expired calibration certificates, and nearly all ongoing auction listings, so no idea as to what they will eventually sell for>

Needless to say, I was talking about new prices.

If you have this much time on your hands, it might perhaps be much more useful to the OP if you did a search of completed eBay listings for such items, so that you could indicate what prices the items actually sold for, and also give an indication of the cost of servicing/recalibration.

Even buying secondhand, I doubt that one would often be able to get a lot of change out of £400 after buying a reliable MFT of a reputable make and getting it calibrated/serviced.

Kind Regards, John

 

[mysearch]

I was hoping that some of the members that helped me understand the issues surrounding installing some new electrical circuits for a new kitchen/utility room might have a quick look at the attached circuit layout.

The proposal is to replace the existing fuse-box and 6 circuits with a 10-way consumer unit (Hager) with dual 80A/30ma RCDs. Looking at the overall current loading, 80A RCD, rather than 100A, seems fine as the latter are quite a bit more expensive.

All the new circuits are radial circuits, such that I have used thicker cables than in a loop design.

Cooker and hob will be on separate 32A MCB radial circuits using 6mm cable. These will be connected to the CU and tested by the electrician.

The new utility mains circuit will be on another 32A MCB radial, also on 6mm cable, although 4mm might be enough – not too sure on this point. Maximum current loading should be less than 20A, but includes washing machine & tumble dryer.

The new utility lighting circuit will be on 6A MCB radial, using 1.5mm cable. Maximum current should be <2A.

The 20A/60A junction boxes are required because this utility circuits will initially be wired up to the existing fuse box and then moved to the CU once all the kitchen rewiring is complete so that any possible problems with RCD current leakage in the existing kitchen might be avoided.

Would really appreciate any expert advice or corrections to the proposal before talking to a professional electrician to be used for the CU installation and circuits testing. Thanks

Untitled

• mysearch
• 11 Sep 2014
• 1

 

[ban-all-sheds]

All the new circuits are radial circuits, such that I have used thicker cables than in a loop design.

Cooker and hob will be on separate 32A MCB radial circuits using 6mm cable. These will be connected to the CU and tested by the electrician.

What makes you think that an electrician will be happy to sign this declaration when he did not do the highlighted activities?

I being the person responsible for the design, construction, inspection & testing of the electrical installation (as indicated by my signature below), particulars of which are described above, having exercised reasonable skill and care when carrying out the design, construction, inspection & testing hereby CERTIFY that the said work for which I have been responsible is to the best of my knowledge and belief in accordance with BS 7671:2008, amended to 2011 except for the departures, if any, detailed as follows:

I was possibly hoping that I might be able to carry out a lot of the installation of the new wiring for the kitchen and utility using the old fuse box, then get a qualified electrician to fit the CU+RCDs+MCBs plus connect and test all new circuits before doing the necessarily notification for me. Is this possible, i.e. would an electrician agree to this?

You might find one, but you'd have to agree everything in advance.

You will not find one prepared to sign a declaration to say he designed and installed the circuits if you present him with your fait accomplis.

You seem to be carrying on with your plan in disregard of the reality that it won't work.

Your idea will not mean that you won't have to apply for Building Regulations approval in advance, and it will not mean that you'll end up with a valid Electrical Installation Certificate at the end.

The new utility mains circuit will be on another 32A MCB radial, also on 6mm cable, although 4mm might be enough – not too sure on this point.

Not good enough. You've decided that you are capable of doing electrical design work, but you aren't sure what cable sizes to use?

What does Ib &#8804; In &#8804; Iz mean to you?

The new utility lighting circuit will be on 6A MCB radial, using 1.5mm cable.

Why that size?

The 20A/60A junction boxes are required because this utility circuits will initially be wired up to the existing fuse box and then moved to the CU once all the kitchen rewiring is complete

Why can't the new cables be left long enough to reach their ultimate destination?

Would really appreciate any expert advice or corrections to the proposal before talking to a professional electrician to be used for the CU installation and circuits testing.

You need to use a professional electrician for all of it, not just connecting your new circuits to a CU and doing the testing.

Thanks

NP.

 

[mysearch]

What makes you think that an electrician will be happy to sign this declaration when he did not do the highlighted activities?

I don’t, that is why I will call in an electrician prior to starting any work.

I being the person responsible for the design, construction, inspection & testing of the electrical installation (as indicated by my signature below), particulars of which are described above, having exercised reasonable skill and care when carrying out the design, construction, inspection & testing hereby CERTIFY that the said work for which I have been responsible is to the best of my knowledge and belief in accordance with BS 7671:2008, amended to 2011 except for the departures, if any, detailed as follows:

I won’t argue about the letter of the regulations, although I am not sure that the ‘real world’ works to such exacting requirements. Of course, if it does, then I will have to paid an electrician to do all the work. However, presumably any electrician fitting a new CU to an existing house would not have ‘designed and constructed’ the original wiring, therefore only ‘inspects and tests’ the operation of the circuits when fitting the CU.

You seem to be carrying on with your plan in disregard of the reality that it won't work.. Your idea will not mean that you won't have to apply for Building Regulations approval in advance, and it will not mean that you'll end up with a valid Electrical Installation Certificate at the end.

Not true, at this stage, I am simply trying to understand what is involved and what design issues need to be taken into consideration. As indicated, I intended to discuss the design with a professional electrician prior to starting any work. If I can’t do any of it, so be it. However, I am not sure that a professional electrician needs to channel out the walls for the cable?

Not good enough. You've decided that you are capable of doing electrical design work, but you aren't sure what cable sizes to use? What does Ib &#8804; In &#8804; Iz mean to you?

Again, not true. I have not decided anything, I am simply trying to understand the issues.

Why that size?

//www.diynot.com/forums/viewtopic.php?t=258334
Again, I am only trying to understand the issues so that I can discuss the options with the electrician. Surely, it is to the benefit of all parties that these issues can be understood by the customer rather than being totally reliant on the electrician, who I assume are not all born equal in terms of qualifications or experience.
http://www.govyou.co.uk/part-p-of-the-building-regulations-scrapped/

Why can't the new cables be left long enough to reach their ultimate destination?

Excellent point to be taken on-board.

You need to use a professional electrician for all of it, not just connecting your new circuits to a CU and doing the testing.

You may be right, but I have tried to explain why I am asking for advice and would still appreciate any further advice on the actual details of the layout. Thanks

 

[JohnW2]

Would really appreciate any expert advice or corrections to the proposal before talking to a professional electrician to be used for the CU installation and circuits testing. Thanks

Notwithstanding BAS's points (most of which are valid), I think that you proposal is conceptually reasonable, and certainly a good/adequate basis for your up-front discussions with the electrician who will be involved.

Your electrician will undoubtedly have views on details of your proposal. In particular, (s)he may well feel that all your proposed cable sizes represent 'overkill' - not just the 6mm² cable for hob and oven circuits that we've already discussed, but also the 6mm² for sockets circuit and 1.5mm² for the lighting circuit. (S)he will probably also have views on the optimum ways to distribute the circuits between the two RCDs in the new CU. BAS's suggestion that enough spare cable be utilised so that the definitive connections to the new CU can be made without the need for joins in JBs is a good one.

Kind Regards, John