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joining main feed with junction boxes under floorboards
Posted: Fri Mar 29, 2013 1:56 pm
by leck
I am a first time blogger on this site , I know a bit about electrics I did a city and guilds in 1987 witch is far out dated I know.
I have recently had a load bearing wall taken out , to cut a long story short I had to fit two RSJs along side each other so I got a flush ceiling fitting, to get to the question I want to ask , I had to cut all the main cables leading from the front of the house to the back and drill holes in the RSJs ,feed the cables through the holes and then I joined the cables back up using junction boxes (I did use the correct amp junction boxes ).
But since I have been told that I need to now have the whole house rewired.
I have been reading your forum about junction boxes having to be accessible and fixed fitting a cross batten in the centre 1/3 of the depth of the joist , in case later someone tries to cut into the ceiling ,I also read the bit about maintenance free junction boxes , all of witch I found very useful.
where I joined the wires above is a landing and directly under the stairs is a ceiling obviously, what I want to know is am I allowed to use maintenance free boxes, and put the floor boards and ceiling back without having to be accessible.
I am now thinking of calling in a qualified electrician to finish the job , its done my head in can you give me rough I how much it will cost me.
Can the the problem be solved with out having the whole house rewired.
please help
Leck
Re: joining main feed with junction boxes under floorboards
Posted: Fri Mar 29, 2013 8:04 pm
by ericmark
You say "main cables leading from the front of the house to the back" which could be anything from 1.5 mm sq for main lights feed to 16 mm sq for feed to consumer unit and that means there are a few different methods. Cable joints vary from epoxy filled containers with crimps, epoxy lined shrink sleeve again with crimps, to spring clip maintenance free junction boxes. It also depends on how the cable is held to if some form of clamp is required.
Personally I find the smaller crimps are not as good as the larger types mainly I think as the cable can move. But using a crimp pliers designed for the crimp used is the major problem. The crimps that fail normally one finds have been crimped with wrong pliers. Using shrink sleeve will normally give a joint nearly as good as original cable. The epoxy resin stops the cable moving near the joint. But with insulation tape the grip is not as firm allowing strain to be put on the crimp.
But to start with please what size cables are you talking about.
Re: joining main feed with junction boxes under floorboards
Posted: Sun Mar 31, 2013 2:13 am
by leck
hello again thanks for your the response,sorry I didn't say what cables they where,
their are about 8 cables in all of which are twin and earth ,
three of the cables are lighting 1.5mm,
and four of the cables are main ring for plug sockets 2.5mm,
one of the cables is 6mm for use of cooker socket.
what is the best method to use in this case, and will it be completely maintenance free ?
I say this because I had a servery-er come in and say the whole house needed rewiring,
most of all will it meet all new regulations ?
finally what would a good electrician charge for all this work?
Thanks for all you help much appreciated ericmark
Leck
Re: joining main feed with junction boxes under floorboards
Posted: Tue Apr 02, 2013 6:51 pm
by ericmark
There are many ways that could be used if it were me and I am a bit rough at times it would be crimp connectors and epoxy lined shrink sleeve. Must be epoxy lined as this will ensure it can't slip off. And also no water can get in if you every have a flood.
With so many cables you would need a really large junction box and although common in Germany not seen any maintenance free types in the country of that size. I have had in the past make my own. The maintenance free terminals do come at DIN rail mount and you can get plastic boxes with DIN rail build in.
However although OK in a factory with resident electrician not so sure where in the home. I was commercial and for the home some things need to be type tested before use.
With a little luck one of the other will pop in on this one.
Re: joining main feed with junction boxes under floorboards
Posted: Tue Apr 02, 2013 6:56 pm
by ericmark
As a PS why did the surveyor say it needed a rewire? When we complete an electrical installation condition report (EICR) was called PIR we have to list down what is wrong. We can't just say re-wire required. Although that may go in recommendations.
Re: joining main feed with junction boxes under floorboards
Posted: Thu Apr 04, 2013 8:29 am
by leck
Well I did said it was to cut a long story short , it was a council surveyor who recommended that but he is not a qualified electrician, I am aware that the council can sometimes have a dim view on such things ,it this was all done in a rush after putting in the rsjs and now, I am in a bit of an argument about it ,and am looking for a solution without chiseling up all the plaster and costing alot of work and money, I realize there are eight cables three lighting cables and four main ring cables for the sockets and one cooker cable.
Its only a two up and two down terrace house do you think using crimp connectors and epoxy lined shrink sleeve and epoxy lined connections will be sufficient ..?, I have looked into some maintenance free junction boxes by a company called Wagobox Electrical Junction Box (can be seen on you tube ) that came out in the uk in 2009 the connections seem fine ,it just that they seem to be needed to put in boxes if you could have a quick look on you tube for me and the joins I need to make ,I dont think have enough slack to fit into the wago concentions and the boxes they supply do you think I can use wago clips with without the boxes supply and get ,anything to get the surveyor off my back and make him happy.
its giving me a headache any help welcome
Thanks
Re: joining main feed with junction boxes under floorboards
Posted: Thu Apr 04, 2013 11:58 am
by ericmark
I would use crimps and shrink sleeve cheap and easy but that's me. Since short on length the Ashley
Maintenance Free Junction Boxes where it goes in one end and out the other may work better for you. Two cables spliced per box. If there is chance of getting wet then "Magic Gel - IP68" could be used to fill the box. I filled one of my voltage testers with the stuff in Hong Kong working on a tunnel.
The connectors the guy shows I used back in 1980 when working in Algeria he may have invented the box but not the connectors.