What is the approved method - or methods - of extending a radial circuit i.e. joining two lengths of twin and earth and placing the joint back into the plaster?
I assume that jointing with the appropriate size of chocolate block might be acceptable, but I am certain that plastering over chocolate block would be illegal.
Thanks.
If the joint is to be inaccessible later (i.e. plastered over) then it must not be made with screwed connectors, so as you rightly assumed, chockie blocks are out). The allowable methods are soldering, welding and crimping (with a proper ratchet crimp tool!).
The easiest is normally to crimp. You need to cover the joined area with heat shrink (and the heat shrink the individual wires if using uninsulated crimps or solder). If you stagger the wire lengths a little so each of the wire joint does not line up with each other you avoid making a big bulge in the cable that might be awkward to heat shrink over
Connections which won't be easily accessible for testing must be crimped, soldered, or brazed. Crimping is the usual method used in the case you describe, but you must use correct crimps for the cable size, and a good ratchet crimping tool. Use insulated crimps and wrap the overall joint afterwards (can use insulating tape, but heatshrink sleaving is much more professional -- remember to thread it onto the cable before you crimp).
Note that the cable run must remain obvious by being a horizontal or vertical run from a visible wiring accessory, or being vertical run near a corner or a horizontal run just below the ceiling. If this isn't the case, then you must leave a visible wiring accessory at the join (which could just be a blanking plate over a recessed back box), in which case you can use a chocolate block connector in the box.
"Martin" wrote
To crimp or not to crimp, that is the question!
Some here will tell you that using crimp connectors and appropriate shrink sleaving is OK for buried joints.
Most will tell you either:
a) Remove existing cable and replace with longer, back to the nearest accessible termination. OR b) Create termination e. g. a socket box with screw terminals and a blanking cover and continue with new cable from there.
Phil
Many thanks for your comprehensive, interesting and very helpful reply. I really didn't know that a soldered joint would be acceptable; that said, I can't say I'd be happy with a soldered joint: I'd much prefer a crimped one. But the visible wiring accessory would be the most practicable choice.
Sincere thanks - I really appreciate this information.
Martin
Sincere thanks. Not having access to - and familiarity with - crimping tool, crimping is not an option Your other options a) and b) make perfect sense.
I'm most grateful for you kind and very informative reply.
Many thanks
Martin
"Martin" wrote
No problem - many people in this group (it would be unfair to single out) have come to my rescue with plumbing/electrical issues. Hang around, you'll learn a lot just from reading other posts.
Just one word of warning, top posting is frowned upon i. e. your response to posts should appear underneath the original message not above. That way comments retain chronological, if not necessarily common sense, order.
Phil
Which is what it says in BS7671, which is why some people (me included) offer it as an option.
Yup, better than a joint if doable, however this can be impractical without causing major damage to finishes etc.
This makes more sense if you actually want a socket at the joint location. Just installing a back box and blanking plate seems like a waste of effort just to accomodate a jointing option that has no advantage over crimping etc.
A decent one is not that expensive. See the top one here:
Thanks - it is an excellent group. I've been keeping an eye on it for maybe 2 years and learned a great deal and also been helped out a couple of times.
As to "top posting" - I've not heard of that before. I use Outlook Express to watch and reply to newsgroups rather than by going to any website. And in my OE all the postings fall neatly into place with my replies falling below and inside the person I'm replying to, unless I have misunderstood the concept. Is it Outook Express causing the problem? I can send you a screenshot of my OE screen if it helps.
Regards
Martin
If you're joining, say T&E, and crimp each cable, and then heatshrink each one, is that sufficient, or do you also do anything to the whole set of cables? It feels like there should be something to replace the sheath...
Ben
No, you need an overall sheath as well; in fact if you are using insulated crimps, then you can do away with the individual heatshrink on the wires.
Yup, heatshrink the lot - overlapping the original sheath a bit either side so that there are no exposed wires.
OE is not the worlds most useful usenet client alas. Have a look at the following for an explanation (and a fix) of the problem:
Probably...
Have a look at one of your posts in google groups, and you can see how we see them.
Job done. OE Quotefix up and running.
Many thanks for setting me straight.
Martin
John Rumm wrote:
Unfortunately your reply is still top posted :-(
Oh, bollocks to Outlook Express.
Guess I'll have to get used to the Google Groups layout.
Sorry.
Mart> Mart>
Test message - think I've fixed the bloody thing now.
Thanks to all for your patience.
Martin
I managed for years with OE.
You just have to do a bit of tidying-up as you move the cursor down to the bottom of the quoted text before typing.
Owain
That looks ok... ;-)
Indeed you have.
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