Clarification of regs -adding socket to ring. What required?

[BrotherKennyH]

Hello all,
This is my first post on what I have found to be a very useful forum.

I have spent many hours trawling through google and regulations. I know the Part P regulations do not stop people from doing DIY electrical work in the home, but I am finding it difficult to see how someone can do DIY electrical work without being a fully qualified electrician.

I have added 2 sockets to a ring circuit. Under the Part P regulations this is considered non-notifiable work.

I am quite happy that I have done a good job, but I have been doing further reading since I installed the sockets.

While this work and other such work in non-notifiable am I correct in assuming that work like this requires a minor works certificate? And if so does that mean that other non-notifiable electrical works also require a minor works certificate, such as changing a socket or ceiling rose?

Is this correct(I hope not)? I am quite happy to do the installation, but I don't have the equipment to test the circuit and I'm not exactly sure how anyway. Also I am aware that someone else can't really provide a minor works certificate for my work, if that is whats required.

Kenny

 

[Paul_C]

The Minor Works Certificate is stipulated by BS7671 ("The Wiring Regs."), so an electrician working to BS7671 would normally issue one.

But as there is no obligation for you to follow BS7671, you don't "need" the certificate in the sense of it being a mandatory, legal requirement.

 

[ericmark]

Paul_C is correct your not breaking a law by not testing only a regulation. However the regulations can be used in a court of law to show for example negligence. So if some one was injured due to a fault which would have been apparent had the socket been inspected and tested as laid out with the regulations you would likely have a problem.

I would not expect any DIY guy to run out and buy a test set (around £750) or even hire one for each job (around £75) but there should be some form of testing.

What you can do without too much expense is use a plug in tester. These come in many flavours from the very simple that just check there is an earth but not how good and that the wires are likely the right way around (although likely can't work out if neutral and earth are swapped). These then start to raise in price until they get to one which does a rough test of earth loop impedance (how good the earth is) and simple RCD test. Cost is from £12 for very basic to £45 to do quite a good test.

Two companies Martindale and Socket&See do a range of testers and Martindale have been around for years. I do question some of the tests the SOK36 has a button to test the RCD but it only does the same as the button on the RCD itself so can't really see the point? The SOK34 or EZ150 depending on which make you go for do a reasonable job personally I would go for Martindale

as it seems to give some sort of level rather than simple go/no go and so more useful. But these

at under £12 will not break the bank and must be better than nothing.

My son did make a very good point. Although I have a full test set it is taken out of it's lovely aluminium case once in a blue moon and is really just taking up space. Where as a socket tester is so easy to use likely it would be used more often. At work we have found more faulty sockets with the PAT tester than with the earth loop impedance tester simply as the PAT tester is used more and since it does a self test each time it is switched on it has identified quite a few faults.

At work every socket should have been fitted by an electrician and tested and inspected with full test kit but we have still found faults. So one should expect to also find faults in the home. In theory when a new occupant or every ten years the home should be tested. In practice this does not happen so at least with a plug in tester you are reducing the risk.

 

[BrotherKennyH]

Thanks for the replies. I feel better now.

I think I will invest in a socket tester. Even if I am not breaking any laws I would like a bit more peace of mind.

Thanks again for the replies.

Kenny

 

[ban-all-sheds]

I would not expect any DIY guy to run out and buy a test set (around £750) or even hire one for each job (around £75)

No, but it's quite feasible to buy kit on eBay for the sort of money that would get you a small hire car on one holiday, won't even get one upgrade one way to Premium Economy on a Virgin flight to Florida, would get you started with a mid-price set of golf clubs etc.

 

[BrotherKennyH]

I'm going to alter this ring circuit again soon (or at least I would like to).

I want to add a socket somewhere else.

When you add a socket to a ring main does it need to use the existing cabling to be non-notifiable?

If I wanted to add a socket further along the house there wouldn't be enough existing cable or if I installed a socket between 2 existing ones, but needed to replace the cable because the height the socket was up the wall meant the existing cable was not long enough. Would those examples be notifiable?

 

[ban-all-sheds]

Schedule 4.

 

[Taylortwocities]

ESC have just added a new title to their quite useful Best Practise Guides.

It deals with plug in testers and details what they can, and cannot do.

Worth a read

http://www.esc.org.uk/fileadmin/user_upload/documents/industry/best_practice/BPG8_10.pdf

 

[ericmark]

There is a problem with final ring circuits in that it is easy for the ring to be broken. Really one does need to check continuity between the pairs as it is quite a large overload should the ring be broken.

It would only require bulb battery and lamp like those kids games where you try to move loop from one end to other but it really should be checked.

 

[ericmark]

ESC have just added a new title to their quite useful Best Practise Guides.

It deals with plug in testers and details what they can, and cannot do.

Worth a read

http://www.esc.org.uk/fileadmin/user_upload/documents/industry/best_practice/BPG8_10.pdf[/QUOTE]
The link is good except for one thing I agree with what they say. But with the professional loop impedance tester you can measure the PSC or impedance between line and neutral both at socket and at CU and use these reading to work out the potential volt drop.

Of course must be between line and neutral not earth and it will require some maths but it will do the measuring required.

I hope I have made it clear that one should be using a low ohm meter with at least 200ma current and a high ohm meter with 500 volt plus a RCD tester able to measure the milliseconds it takes to trip. And also having a reading rather than a go/no go light is far better. In fact required to complete a minor works certificate. However I am enough of a realist to realise people will not do it and at least with a plug in tester it will identify some of the errors rather than just trusting to the Lord.

I have not a clue what instructions come with the plug in units and if they help you identify what the reading should be? With the three start points of 0.35 ohm, 0.8 ohm and 200 ohm different earthing systems could mean sockets have very different results which could both pass according to earth type and MCB size including if B, C, or D type. I some how would not expect the instructions to cover all this!

 

[BrotherKennyH]

BAS,
I appreciate what it says in schedule 4, particularly about new fixed cable.
The things is that replacing damaged cable is non-notifiable and adding a socket is non-notifiable. I cannot see how extending the circuit is different, in terms of overall electrical connections. I appreciate you have to take cable length into account, but in a normal size home I can't see the additional distance being significant.
Also, unless you need a long distance no one would even know it had been done if the wiring colours hadn't changed so I have been half expecting there to be an exception somewhere that I haven't found yet buried in some obscure clause.

Taylortwocities,
From the looks of that best practice guide the tester I have ordered is considered an advanced socket tester because it identifies the earth loop impedance. Good to know.

Correct my stupidity if I am wrong, but isn't the only way to test the continuity around the whole ring to disconnect from the MCB and test from there?

Thanks again for the replies guys.

Kenny

 

[Paul_C]

BAS,
I appreciate what it says in schedule 4, particularly about new fixed cable.
The things is that replacing damaged cable is non-notifiable and adding a socket is non-notifiable. I cannot see how extending the circuit is different, in terms of overall electrical connections.

Extending an existing ring and adding sockets to it is generally not notifiable, unless the work is in a kitchen, bathroom, or outside. See para. 2 of schedule 4.

Correct my stupidity if I am wrong, but isn't the only way to test the continuity around the whole ring to disconnect from the MCB and test from there?

It's a ring. If you break into one of the conductors at any point on the ring, you should read continuity between the two ends.

Imagine a circle. Now make a break in that circle at any point you like. The two ends either side of your break will still be joined together by the rest of the circle.

 

[PrenticeBoyofDerry]

BAS,

Correct my stupidity if I am wrong, but isn't the only way to test the continuity around the whole ring to disconnect from the MCB and test from there?

Kenny

To test for continuity of the RFC, you will indeed need to remove the two phase legs from the MCB and the neutral from neutral bar and the same for earth/CPC
You check end to end resistance of each conductor, this will give you a valve.
The Phase conductor should very close to the same reading as the neutral conductor,within 0.05 ohms.
The CPC/earth end to end resitance will be higher if the CPC is a smaller CSA. 1.67 times for 2.5/1.5 T&E.
Then connect the opposite legs of each phase and neutral together, forming a loop. If you take a measurement across them at the board, that reading should by within 0.05 ohms at each socket outlet.
This will be about 1/4 of the value of the phase and neutral readings, when added together.
Any socket with a bad connection or a spurred socket will give a higher.
reading.
This test is then repeated using phase and CPC.

Now then extending the RFC, certificates required are either a minor works or an electrical installation certificate. Minor works are easier to fill in.
Do you have RCD protection on this circuit, because any alteration if not complying to certain methods of installation, will require the addition of RCD protection.
Installing a RCD at the board will then become notifiable work.

 

[JohnW2]

BAS, I appreciate what it says in schedule 4, particularly about new fixed cable. The things is that replacing damaged cable is non-notifiable and adding a socket is non-notifiable. I cannot see how extending the circuit is different, in terms of overall electrical connections.

As far as I am concerned, nothing in Schedule 4 says that 'extending' a (ring or radial) socket circuit is notifiable (provided it's not in a kitchen or special location). As you say, the addition of sockets or fused spurs is explicitly indicated as non-notifiable, and what is that if it is not 'extending' the circuit? It's obviously implicit that the (non-notifiable) addition of sockets includes new 'fixed cable', so that clearly does not make the work notifiable

You are right in recognising that a very lengthy 'extension' of a socket circuit could introduce some electrical/engineering issues that should be considered - but I see nothing in Schedule 4 that says that adding sockets to an existing circuit would ever be notifiable, even if the cable were 50 metres long!

Kind Regards, John.

 

[securespark]

It's a ring. If you break into one of the conductors at any point on the ring, you should read continuity between the two ends.

Imagine a circle. Now make a break in that circle at any point you like. The two ends either side of your break will still be joined together by the rest of the circle.