Hi In a number of posts to UK DIY, people are advising the use of crimps to join cables, The use of insulated crimps to join solid copper conductors can cause fire. Their are manufacturers who will imply that their crimps will safely join solid copper conductors, They dont. Today I have been to my 3rd breakdown this year where a crimped cable has broken down and caused damage. Insulated Crimps are only for Stranded copper cable, not Solid Copper as is found in domestic Flat Twin Cables. Bob James
I've always thought this, but thought I'd be in a minority of 1. I wonder if folding the wire double and using an uninsulated crimp would be better, so each wire gets held by the blade at each side which would then curve into the middle.
"Screwits" is one brand name. A nicname they had back in the days they were used was "dog bollocks" due to the way a pair of them would hang down below a cable. They are still allowed and commonly used in the US, who call them wire nuts, and are a significant source of building fires.
Note that there are crimps which look similar too.
The problems that I have had with Crimped Cables has been confined to
2.5 Flat twin with Solid conductors and includes Crimps that have been compressed with a Professional tool. I Have, today, joined 8 different pieces of 2.5 with Insulated Crimps using a ratchet tool, This seems to compress in 2 areas on each side of the cable only and when the joints are cut open the solid copper cable has only 4 slight marks on it. None of the joints came apart easily or showed any movement after crimping. I have used this method for joining damaged cables in walls myself but will not use it in future Regards Bob
Funny, when I google "wire nut fire" the only result is
formatting link
includes me questioning a post in this group about the basis for the perception that wire nuts start many US building fires.
Wire Nuts when properly installed do NOT overheat!
It is not difficult to correctly apply a wire nut!
It should be noted that US wiring codes require ALL splices to be in junction boxes. If a mis-applied wire nut were to overheat and start the insulation on fire, it would be contained and not lead to a structure fire. By the way a wire nut getting hot enough to start an insulation fire is an extremely rare occurrence. In fact it is so rare that statistics seem impossible to find!
I have hundreds of wire nuts in use in my home, I don't lose any sleep over their safety.
Part of my reason for reading this group is to find better ways of doing things by broadening my knowledge base.
It seems strange that many otherwise enlightened people persist in believing cross Atlantic stereotypes.
Aluminium wiring is common in the USA. When aluminium wiring is combined with wire nuts, overheating and fires result.
formatting link
It should be noted that US wiring codes require ALL splices to be in
That's by no means clear, according to the above website. This sequence of photos make it clear it's possible for fires to travel along the wire insulation and out of the junction box, possibly spreading to the house structure:
"Common" is a wild exaggeration, "not unheard of" is closer to the truth. Approximately 2 million homes were wired with Aluminum wire between 1965 and 1973. Most of these were manufactured homes (AKA mobile homes, see Jerry Springer) that have by now, far exceeded their useful life (estimated at 19 years by the Gov.). The vast majority of the Aluminum wire in normal structures has been replaced by this point and it never amounted to much in the first place. Many a modern electrician has never seen it in person.
When small gauge Aluminum wiring is combined with anything, fires result. Once this fact of life was realized it's use was discontinued in 1972/3.
I just went to the garage and tried to duplicate the experiment. I could not light an Ideal brand wirenut with a match, so I pulled out the trusty Oxy-Acetylene torch and melted it, even when quite liquid it was still self extinguishing. as was the wire insulation I tested next.
I did not have any Noalox handy to test, but the Ideal web site lists it as Non Flammable.
Your second link shows what is more likely and again this is the rare Aluminum wire.
replace it as soon as practical. Just as I assume you would if you encountered ancient cloth and crumbling rubber insulated wire.
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.