DIY Forum

DIY Forum/Home improvement advice

 

 

A-Z CONTENTS | ARCADE | DISCLAIMER | DIRECTORY | DIY VIDEO | HOME | SAFETY FIRST | FORUM RULES

It is currently Wed May 23, 2012 2:20 am
Visit Buck and Hickman


Time zone: Europe/London [ DST ]




 

Post new topic This topic is locked, you cannot edit posts or make further replies.  [ 6 posts ] 
Author Message
 Post subject: Butt Crimps
PostPosted: Sat Dec 31, 2011 3:06 am 
Offline
Newly registered Member

Joined: Sat Dec 31, 2011 2:35 am
Posts: 30
Location: Sheffield SYorks
Has thanked: 7 times
Been thanked: 1 times
I am going to replace my consumer unit with a modern one, the one at present is well out dated, has mcbs but no rcd protection for the whole house. problem i have is the old wireing red black green do not or will not reach most of the terminals in the new box. all the old wires will enter from the back from one hole in the wall and plastered, no slack in the wires either. will it be OK to butt extension wires onto some of the old wires, a re wire is not feesable, a lot of advise would be helpfull. would block screw terminals be accepable for inspection? :withstupid:


Top
 Profile  
 
 Post subject: Re: Butt Crimps
PostPosted: Sat Dec 31, 2011 7:34 am 
Offline
Senior Member
User avatar

Joined: Wed Dec 31, 2008 9:23 am
Posts: 1152
Location: Down on the Farm
Has thanked: 10 times
Been thanked: 75 times
Butt crimps properly installed everytime. Dont be tempted to use choc blocks and I would not use wago's either but thats just a personal thing.



For this message the author Sparky James has received gratitude : £££sjim
Top
 Profile  
 
You may not be able to see the full post including pictures unless you register or log in

 Post subject: Re: Butt Crimps
PostPosted: Sun Jan 01, 2012 2:36 pm 
Offline
Newly registered Member

Joined: Sat Dec 31, 2011 2:35 am
Posts: 30
Location: Sheffield SYorks
Has thanked: 7 times
Been thanked: 1 times
thanks sparky jim, studying for part P. just wondered where we stand regarding joining the wires in a consumer box? :withstupid:


Top
 Profile  
 
You may not be able to see the full post including pictures unless you register or log in

 Post subject: Re: Butt Crimps
PostPosted: Mon Jan 02, 2012 1:01 pm 
Offline
Senior Member
User avatar

Joined: Tue May 10, 2011 3:43 am
Posts: 427
Location: North Wales
Has thanked: 6 times
Been thanked: 96 times
I have used the shrink covered butt crimps which do a very neat job. But one needs the correct jaws to ensure the crimp is correctly applied. In all my time as an electrician only one firm I have worked for ever calibrated the crimp pliers. That was GEC Large Steam Turbines who I worked for in Sizewell and Connah's Quay power stations. But it did raise the question as to matching cable size to the crimp used. 1.5mm, 2.5mm, and 6mm cable in red, blue, and yellow crimps is normally not a problem. But 1mm and 4mm cable is really too small to fill the red, and yellow crimps and needs special pliers to ensure it is correctly crimped.

GEC issue crimp pliers would impress a number onto the plastic so an inspector could check if the correct pair of pliers had been used.

So although a correct used crimp is fine one must use the correct pliers for the crimp. With the blue crimp for example there are different jaws for the shrink type to non shrink type and to be certain one would have to use same make of pliers and crimp.

Personally I just look at the crimp and give it a small tug although really one should not tug at them. Only the test crimp made to calibrate should subjected to any force.



For this message the author ericmark has received gratitude : £££sjim
Top
 Profile  
 
You may not be able to see the full post including pictures unless you register or log in

 Post subject: Re: Butt Crimps
PostPosted: Mon Jan 02, 2012 5:32 pm 
Offline
Newly registered Member

Joined: Sat Dec 31, 2011 2:35 am
Posts: 30
Location: Sheffield SYorks
Has thanked: 7 times
Been thanked: 1 times
thanks ericmark! i have a decent set of crimpers that wont release till correct pressure is reached, slots colour coded, although some times it's hard getting the pressure to release the jaws,lol :withstupid:


Top
 Profile  
 
You may not be able to see the full post including pictures unless you register or log in

 Post subject: Re: Butt Crimps
PostPosted: Wed Jan 04, 2012 1:10 am 
Offline
Senior Member
User avatar

Joined: Tue May 10, 2011 3:43 am
Posts: 427
Location: North Wales
Has thanked: 6 times
Been thanked: 96 times
I have two sets of crimp pliers which have a over centre mechanism which controls the pressure. One the standard one where you need to completely close to re-open. The other set looks like a pair of mole grips. Latter has not been used for years but has a locked adjustment at end of grip. The other pair has a dial to adjust the pressure.

What I have talked about with a number of sparks is under pressure is something which we can see or at least feel as when we tug the crimp will come off. However over crimping needs one to remove the crimp and inspect the cable to see the effects. I have seen where the cross sectional area was reduced due to the crimp pliers being wrongly set.

However the consensus was that although the cable was crushed it was unlikely to cause overheating as a result so was not really a problem. What we considered was more of a problem was the oxide and the thin plastic coating put on cables where under low light conditions it can easy be missed.

So I am quite happy to use my over centre crimp pliers even though not calibrated.

However I had a lot of problems using crimps with motor vehicles because of the very close contact capillary action tends to keep them wet and with the salts acting as an electrolyte the electrolytic action can quickly cause them to fail.

With motor vehicles I found connector strips in junction boxes worked better.

I think therefore one must use some thought as to what one is doing and not just follow an instruction set. There may be situations where using a junction box does a better job than the crimp specially where the crimps make the space in the consumer unit crowded.

With non domestic I have built my own panel with a din rail full of connectors to address the problem of short cables. However for domestic we should use type tested units.

I have argued with my son over the enclosure in my house which holds the two RCD's. He says it not allowed in a house as there is not an Instructed, Skilled or Competent person on site. However I pointed out to him, I am classed as Competent, so is my father-in-law next door but one and so is he. Also my father was the Technician Engineer in a 1000MW power station and my son-in-law studied for his degree in electrical engineering so every house hold in the family has a competent person resident.

However I have found the more knowledge I gather the more I realise that I don't know. And one can get totally bogged down with regulations so I have been looking at this smiley while I was typing so can't resist. :dunno: :dunno:



For this message the author ericmark has received gratitude : £££sjim
Top
 Profile  
 
You may not be able to see the full post including pictures unless you register or log in

Display posts from previous:  Sort by  
Post new topic This topic is locked, you cannot edit posts or make further replies.  [ 6 posts ] 


Similar topics
   

Time zone: Europe/London [ DST ]


Who is online

Users browsing this forum: No registered users and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
cron


News News Site map Site map SitemapIndex SitemapIndex RSS Feed RSS Feed Channel list Channel list
ultimatehandyman privacy policy

Contact

 

Powered by phpBB® Forum Software © phpBB Group

phpBB SEO

 

Diy forum - Decking - plastering - Plumbing - DIY - Tiling