New circuit

[Andygasman2010]

Hi Guys.

I'm currently renovating 2 bedrooms in my house and I'm installing 5 sockets in each room on one ring straight to/from the CU.

It's almost done but I'd like to know if there are any tests I should be doing on the circuit before connecting it to the CU.

I have a Fluke 116 and one of these loop testers...

http://www.socketandsee.co.uk/produ...ket & See PDL234 Plus Part P Loop Testing Kit

Thanks
Andy

 

[EFLImpudence]

There are several tests -

Edit - link deleted - nothing there.

Order of Tests -
Continuity Testing
Insulation Testing
Polarity Testing
Loop Testing
RCD Testing
Functional Testing
Certification

Also, for information, new circuits are notifiable work.


Edit - the Socket & See you link is not really sufficient and you should be aware of what it canNOT detect.

 

[riveralt]

If this is not a wind up then you have to ask the questions why don't you know and/or why didn't you find out before you started the project?
Firstly, what are you design criteria?
What type of earthing do you have?
Is you main protective bonding in place?
Why did you select a Ring Final Circuit?
What size and type of cable are you using?
What size MCB are you using?
Is the circuit additionally protected?
Is the cable in the safe zones?
Do the Local Authority Building Control need to be informed?

For Testing do you have an appropriate tester?

Does it test for Continuity, Insulation Resistance, voltage, RCD etc?
Do you know how to conduct these tests and more importantly how to interpret the results?
Do you know how to fill in an Electrical Installation Certificate?
etc etc etc....

 

[Andygasman2010]

Thanks!

I'm getting a sparky in to do the lighting and mains smoke alarms so what do think my chances are of getting him to test and cert. the circuit I've fitted?

Bit cheeky I know but I was at that stage with the walls and plastering so I decided I may as well run the cable around the back boxes I'd just fitted.

 

[Andygasman2010]

Firstly, what are you design criteria?
What type of earthing do you have?
Is you main protective bonding in place?
Why did you select a Ring Final Circuit?
What size and type of cable are you using?
What size MCB are you using?
Is the circuit additionally protected?
Is the cable in the safe zones?
Do the Local Authority Building Control need to be informed?

For Testing do you have an appropriate tester?

Does it test for Continuity, Insulation Resistance, voltage, RCD etc?
Do you know how to conduct these tests and more importantly how to interpret the results?
Do you know how to fill in an Electrical Installation Certificate?
etc etc etc....

Not sure what exactly you mean by design criteria.

I have a TN system

It has bonding in place to gas and water pipes (10mm)

Why wouldn't I select a ring final circuit?

I've used 2.5mm T+E

There isn't an MCB yet as it's not connected up, it will be a 32A.

Cable is mostly in the safe zones but where it isn't I've used galvanised steel protection and earthed it to the appropriate back box.


Any advice and/or ear bashing welcome!

 

[Andygasman2010]

If this is not a wind up then you have to ask the questions why don't you know and/or why didn't you find out before you started the project?

It kind of snowballed really. I fitted the back boxes and channels intending to get a sparky in but then I was ready for plastering so instead of waiting around I just ran the cable. It just meant I could get on with other things.

 

[EFLImpudence]

Not sure what exactly you mean by design criteria.

Circuits should be designed for loading, protection etc. -
although a standard Ring Final is just that - a standard.

I have a TN system
It has bonding in place to gas and water pipes (10mm)

Ok.

Why wouldn't I select a ring final circuit?

Not really necessary for bedrooms with small loads - 16A radial would be adequate.
It does depend on route and situation.

I've used 2.5mm T+E

You would.

There isn't an MCB yet as it's not connected up, it will be a 32A.

Ok if cable doesn't run through thermal insulation.

Cable is mostly in the safe zones but where it isn't I've used galvanised steel protection and earthed it to the appropriate back box.

3mm. thick?

Why would you not keep to the safe zones or...
...what, in a bedroom, made it necessary to install the cable elsewhere?

New circuits must be protected by an RCD.

Electricians cannot certify other people's work although, obviously, it can be tested.

 

[Andygasman2010]

Thanks for the pointers.

Looks like I've gone a bit overkill with using a ring circuit then, but it's barely any more cost/work so why not ey!

There is no thermal insulation so that's OK.

The non-safe zone is two doubles at about chest height (for a TV etc... on a unit) and I've chased it once up the middle then left and right to each socket then protected the vertical length. I'm pretty sure it's not 3mm thick though, Doh!

 

[Taylortwocities]

You are OK if the sockets are next to each other. If not you should have gone vertical up to one socket and then left, or right, to the other.

Please note that galvanised capping, earthed or not does not constitute adequate mechanical protection.

PS Re getting an electrician to certify your work. Would you sign off a gas boiler installed by an electrician? I thought not.

 

[Andygasman2010]

Thanks for the capping info, I did think it looked a little flimsy. What product is best to use?

I see what you mean about signing off other peoples work but I'd be happy for someone to connect up and test only.

 

[Lectrician]

The non-safe zone is two doubles at about chest height (for a TV etc... on a unit) and I've chased it once up the middle then left and right to each socket then protected the vertical length. I'm pretty sure it's not 3mm thick though, Doh!

What did you use? Steel conduit bushed into a backbox would be the best bet. Using the steel capping available in the stores is no good at all.

Why couldn't you cover vertically up below one of the other sockets?

 

[Andygasman2010]

I did use that steel capping and it does seem pretty useless! I think it'd easier to just reroute the cable into a safe zone.

 

[ban-all-sheds]

I did use that steel capping and it does seem pretty useless!

Which you would have known had you actually been competent to do the work you decided to do.

 

[ericmark]

If you want to do it right then you have left it too late. The LABC has to be informed before you start. The only way you can really do it and comply is not to connect direct into consumer unit.

Although BS7671 considers anything from a new protective device as a new circuit for some reason Part P does not consider a fused connection unit as a new circuit. So feeding from FCU would be only way now to comply.

We can all try to bend the rules and make them fit what we want to do but we are only kidding ourselves.

Anyway forgetting about rules the important question is if it's safe. Well the testers you have linked to will not test installation resistance, RCD operation time, and at 0.1 ohm as lowest reading not much good for testing as a low ohm meter either. However likely between the two meters a skilled man could do enough tests to ensure it is safe except for the RCD test. Clearly you can't measure 40ms with a stop watch.

Of course 9 volt is very different to 500 volt but you at least will get a reading to enter on the certificate.

Down load the IET Forms for the 17th Edition and fill in the questions and following the form will mean you will test most of what is required.

The metal capping is a problem as it effectively means the walls contain metal making it harder not easier to comply. Only reason it was used is it did not flex as much as plastic stuff so easier to plaster.

But you can't comply completely anyway, so it's like asking should I wear a seat belt when doing 60 MPH through a 30 limit?

I see no reason for 32A in a bedroom. I would use max 20A. At least then if there is a break in the ring you still will not overload the circuit.

 

[Andygasman2010]

I did use that steel capping and it does seem pretty useless!

Which you would have known had you actually been competent to do the work you decided to do.

Obviously.