Use of chocolate block?

[Patrick]

Hi,

I'm no spark so if its anything more than changing a fitting I won't touch it.

I recently had the kitchen retiled. The previous owner was a diy-bodger and has made my life miserable with jobs taking 2-3 time longer as I put right what he put wrong. He had originally tiled the kitchen and tiled around the sockets and switches and then grouted the whole lot including the switches. So with the new tiles comes new fittings. The wife wanted the flat plate chrome type. No problem I made sure that all the back boxes were earthed and took a earth from the box to the fitting.

However there was one un-switched spur beside a double socket that caused me a problem:

The spur was fitted with a 2 amp fuse and used to supply the extractor hood. When the screws to the spur plate were removed there was no give in the wiring so I could literally only pull it about 1" from the wall. Once I disconnected it, I could see that on the feed side there were three sets of mains cable (3 live, 3neutral) the third mains used to double socket (must be a addition to the original installation) next to the spur. I knew straight away that I was not going to be able to fit the new spur due to the length of the cables not giving me any room to manoeuvre.

What I did and I'm just wanting to check that this was a legitimate thing to do was to use a 15amp chocolate block to combine the mains cables together (3 live into one and 3 neutral into another) I then got some ring mains cable from homebase and used a few inches of this to connect the chocolate blocks to the feed of the fused spur.

Is this ok?

TIA

Patrick

[Dave]

Patrick wrote: [...]

Don't see why not - so long as you tightened up the screws properly!

Dave

[John Rumm]

Sounds fine in principle, although I would probably have used 30A chocky blocks.

[Patrick]

Thanks Dave and John for the replies.

I do tend to be cautious when it comes to electrics - as an example because of this deviation to the 'normal' wiring I've just ordered wylex plug-in MCBs to replace the rewirable cartridges in my fuse box. I do want to replace this with a modern split consumer unit with RCD but funds just won't permit this just now.

I was wondering about the rating of the choc, as when I checked the quantity and rating of the fuses (to order the MCB equivalents) I have three 5 amp, one 20 amp and two 30 amp.

Do you think its worth while replacing the choc block with a 30 amp?

[John Rumm]

It is not really much of a deviation from "normal"

Assuming that you have the two ring cables (or better still all three wires) stuffed in one end of the chocky block then I doubt it makes any difference in practice. A good proportion of the current carrying contact area will be made up by direct contact between the wires.

[Jim Gregory]

----Aren't there 3 earths now, too? You haven't clarified this. If none were present originally, that was a bodge.

----And maybe 3 earths??

Use the size of choc-block barrel to accommodate comfortably four x 2.5mm2 conductors (at the most 30A), assuming there is enough space for 3 of these inside the back box. Ways can be segregated to suit. Machine screws must be tight. Jim

[Patrick]

Yep sorry - there are three earths also.

I might raise the rating - just to make the fit a bit more comfortable the

15 amp was a tad tight, but I thought it to be the correct rating for a ring main.

This is the second fitting I've found like this. The first I managed (just) to fit directly, but it took about a half hour and a lot of swearing. I've no idea how he (or whoever) managed to wire the spur. Its almost like he fitted it, and then went to the other ends of the cables and pulled them tight.

[Harry Bloomfield]

I suspect the rating is only a guide to the size of cable it can be used with, rather than an absolute rating for the connector. Many of these appear to be brass plated steel anyway. If the hole is large enough, most of the contact area will be due to contact between the actual cables. I dislike the use of the cheaper chocolate blocks anyway for higher currents as the slightest resistance can generate heat and the plastic used has quite a low melting point.

[Rick Hughes]

Messy but not uncommon, adding in a short extension like this is OK as long as all connections are enclosed (which they are) so it is OK ... but change out the connector block to 30A (or higher)

Rick

[adder1969]

The choc block needs to remain accessible though doesn't it? No plastering it into the wall.

[Rick Hughes]

Whta I meant was that the choccy block be enclosed within the wall box .. that way it is both safe an accessible.

>

[Ian Stirling]

Another useful tip may be to intentionally turn the screw on a new choccy block type until it breaks, to get an idea of maximum torque. (this is not an indication of how hard to tighten, but with some, it's possible to strip it, or break the casting (?) without noticing.)

[Patrick]

Thanks to all who replied.

I took it apart at the weekend and swapped out the 15 amp for a 30 amp choc