Replacing damaged cable - crimp or ????

[miker7]

Hi,

After a less than impressive performance by a company replacing my boiler and doing some electrical work i'm now sorting out the mess left behind.

The spark added a socket as requested. To do this he split the ring main in the floor space using chocboxes and extended the cable (and therefore ring) to the new socket. Unfortunately he left the sockets far to high in the wall despite me cutting a channel to the floor. Having inspected the work (aka replaced all the damaged floor boards, it also looks like one of the cables insulation has been nicked (along with one of the water pipes!).

The chocboxes (Screwfix labelled lighting ones) have what looks like helacon plus push in connectors, the two wires taped together and no strain relief. Can i cut these out, use the new screwfix chocboxes, replace the damaged wiring and extend it to the correct length (another 2 feet) and crimp this using the screwfix blue crimps for the 2.5mm and red for the earth, then use the strain relief in the choc box?

I've got a ratchet crimper before someone mentions it.
If i do crimp, is there anything i should look out for (I've had a practice and seem to have created strong joints on some spare wire i've got).

 

[ericmark]

I can't find any suitable junction boxes in screwfix. Although one could use an adaptable box you only have the gland to retain the cable and if using a metal gland then it really should be earthed.
Where the cable is clipped then there should be no need for a cable clamp in the box.
Screws are out. No screw terminals should be used where one can't get easy access so it is spring clip type connectors, Crimps or western role and solder.
However I would not want to alter what an electrician had signed for and would think calling him back to correct his work is the way to go. Remember it will need testing after you complete the work and the test kit is expensive so better to let him correct what he has got wrong.

 

[miker7]

I can't find any suitable junction boxes in screwfix.

This is what he's used -> http://www.screwfix.com/prods/46538/Electrical-Supplies/Cable-Accessories/Connectors-Blocks/Chocbox

and these are what connects the cable, http://www.hellermanntyton.co.uk/products/classifications/products?PRODUCTID=148-90000

However I would not want to alter what an electrician had signed for and would think calling him back to correct his work is the way to go. Remember it will need testing after you complete the work and the test kit is expensive so better to let him correct what he has got wrong.

With the list of things that have been done incorrectly i'm loath to let anyone from the company back in the house - they've been back already to fix the first lot of obvious problems i found - i'd rather do it properly myself.
(and i didn't go with the cheapest quote).

 

[swift2]

Hello Miker 7, I was just reading your post when i noticed the electrican used 'what looks like helacon plus push in connectors' as this is a ring circuit I dont think it is suitable...http://www.hellermanntyton.co.uk/products/classifications/products?PRODUCTID=148-90000
If you look on this website the helacon connectors max current is 24 amps, while your ring circuit would most likely to be protected by a 32 amp mcb/rcbo.

 

[miker7]

I've looked at this and had the same worry, then read some more (i'm not a spark so i don't really know what i'm talking about).

The 32 amps is supplied via a ring of two 2.5 mm cables. Each cable in itself can't deliver 32amps hence its important the ring isn't broken. One cable (normal twin and earth 2.5mm) insulated in a wall can deliver about 23 amps so the connectors are actually ok.

Could a qualified electrician answer the question - has the original electrician made a mistake?

 

[holmslaw]

..

 

[Taylortwocities]

On a 32a ring circuit the cable must have a minimum rating of 20A, so those connectors are ok.

All this assumes that the ring circuit was (and is) correctly designed and installed.

So it will be OK for me to use a 20amp junction box to join a ring up?
I don't think so
Why do they bother making 30amp ones then?

 

[holmslaw]

..

 

[miker7]

The other poster may not thank you - but i have.

So, back to the original question and after fitting the lounge cabinets it looks like the sockets will actually be an acceptable height so its just a like for like cable replacement.

It seems the spring connectors are the fastest solution (and the local wholesaler sells them). Which are better, crimps or the spring connector?

 

[Click-Sure]

Crimps every time for me, stagger the joints and use heat-shrink tubing over the lot.

Jobs a good-un

 

[Taylortwocities]

Don't forget to thank me for improving your electrical knowledge again, the last time you just went very quiet.

My view is that installing a device that is rated at 20A on a circuit that has a CPD of 32A is bad practice. The 20A JB may be positioned at the point of maximum load of the ring final and that could, over time, compromise the integrity of the junction.

If I look at this BS6220 20amp junction box, it says "1.5mm² cables max". That doesn't look like something suitable for a standard ring final in 2.5mm².

I haven't trawled though the regs, but if you think you desrve a

Untitled

• Taylortwocities
• 9 Sep 2009
• 34

then there is one, just there.

 

[holmslaw]

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[Taylortwocities]

At no point in my response did I quote any reg, at all.
I said

My view

.