Ring/radial

[mahutchinson]

Having done Part P I am having a go at upgrading my electrics but have realised that although having the theory is fine the practicalities are more challenging. I've started with the first floor which seems to be laid out as follows:- starting from the dormer room in the roof there is a radial circuit of four sockets. The originating socket has two other cables going down to the first floor. One serves three sockets and ends. The other serves three sockets and (presumably, as the room in question is wooden floored and I haven't checked yet) goes straight back down to the fuse box.

I have two questions - firstly, is this an acceptable setup as it seems to be three separate radials originating out of one socket and there are thirteen sockets altogether ? Secondly, I have five pairs of 2.5mm coming out of the fusebox and under the top of a wooden plate with the fuse and meter on it (up, down, cooker, garage and kitchen) but only four pairs coming out of the bottom of the wooden plate going under the floor. Not sure where the fifth pair goes ? If the up and down circuits are radial as appears to be the case then there should only be eight cables altogether anyway (three pairs and two radial).

 

[333rocky333]

what size is the fuse/mcb

 

[Johnmelad502]

Any chance of some pictures of the CU with the cover off. We like pictures we do.

 

[mahutchinson]

The up and down "rings" are both 32A. This isn't a great pic but there are five pairs of 2.5 going in the top and four coming out the bottom of the wooden plate. Sorry, just realised you asked for cover off. I'll do that tomorrow if necessary. It's just occurred to me that it's actually just one radial from the dormer to the fusebox with another radial of three sockets spurred off the originating dormer socket but I don't think even that is correct under current regs.

Untitled

• mahutchinson
• 2 Apr 2010
• 1

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[333rocky333]

A radial can have branches of it, but a 2.5 wired one would rarely be fused above 16/20 amp.

 

[mahutchinson]

The guy who owned the house before us was a bodge up artist (did property maintenance as a job amazingly) so I'm not surprised at what he's done. Perhaps it was a ring originally and he broke it to extend it into the dormer. There are several junction boxes on the first floor. The dormer room is about 9 years old though and signed off by the council - would they not have looked at the wiring ?

 

[Taylortwocities]

The dormer room is about 9 years old though and signed off by the council - would they not have looked at the wiring ?

9 years ago there was no statutory legislation for electrical works. Except for HASAW etc.
Many builders did their own sparking. Now you are beginning to see why Part P was introduced.

 

[mahutchinson]

I'm still mystified about the number of cables in the CU. Guess I need to look inside the CU/post a pic as requested. As for the circuit, I'm assuming it needs to be either made into a ring or rewired 4mm/20A. There are 12 sockets altogether and I think it is under 50m but have to check that cos of the dormer. The work to add the dormer to a ring wouldn't have been any more than the work to make this bodge up so far as I can see. I'm going to have to change the CU anyhow as part of the work as it has no RCDs currently.

 

[riveralt]

Having done Part P I am having a go at upgrading my electrics but have realised that although having the theory is fine the practicalities are more challenging.

I'm intrigued to know how you do a Part P?

Since Part P is about the Building Regulations and not how to design, install and inspect and test circuits.

What about 2330, 2381 and or 2391 or better still many years experience.

I applaud you asking the question, but are you sure your competent enough to make these upgrades?

 

[mahutchinson]

My Part P course covered all ring main testing. Even the pre-part P introductory course I did covered some. It's difficult to start off with many years experience when you are required to complete two inspected installations before you can join an institute. I'm a bit old to become an apprentice.

 

[Johnmelad502]

You're misinformed. Part P covers all ring main testing.

Part P is part of the building regulations. F.A. to do with testing!

 

[mahutchinson]

You're misinformed. Part P covers all ring main testing.

Part P is part of the building regulations. F.A. to do with testing!

Would you like to see my course notes or the syllabus ?

 

[riveralt]

My Part P course covered all ring main testing..

But clearly not Radials.

Even the pre-part P introductory course I did covered some. It's difficult to start off with many years experience when you are required to complete two inspected installations before you can join an institute. I'm a bit old to become an apprentice.

But surely the course covered the difference between ring circuits and radials - how they are wired and how they are not. How they connect to the Consumer Unit. You must have designed and built both rings and radials on a test board at least - and of course tested them and completed the relevant certificates.

Surely it wasn't all theory?

 

[riveralt]

I hesitate to say this but have you had a look at the wiring inside the Consumer Unit.


Oh and Watch that torch doesn't fall on you.


Alternatively have a look in your Red Book at Appendix 15- you might get some clues there.

 

[martinxxxxxx]

Would you like to see my course notes or the syllabus ?

Er Don't get me wrong I am not trying to pick on you, but i would like to see the booking form for the course (not your details) but the bit where the title of the course is and the fee involved. Or a link would suffix if this is difficult.

If they called it a Part P course giving you a Part P qualification, it would be very interesting.

The point is;- after doing a course you should be able to join one of the competent person schemes. They will ask you questions about redials and rings and cable sizing in quite some detail in my experience.

As for the two jobs one can be your house and the other can be ongoing work in progress with most as I understand it.

Cheers Martin