Talk:Cable crimping

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Might be worth mentioning that both crimped and soldered joints are liable to compromise insulation, especially in inexperienced hands. Insulating each crimped wire before bundling and taping the lot is thus more reliable. Minor point. NT 16:50, 16 May 2007 (BST)

Good article. Might be worth adding a bit about the length of the exposed conductors, since many crimps don't incorporate a stop at the half way point. There is a risk then that the wire of the second crimp is not inserted fully. Cheers, John.

Yup, prolly worth mentioning. I will hack it later.... --John Rumm 17:08, 27 August 2007 (BST)

Is a hairdryer with hand over the air intake hot enough to shrink it?

Sounds like a good way to knacker a hairdryer! The other difficulty is that most hairdryers blow hot air all over the place - you really need the heat to be well focussed; especially on the smaller wires, otherwise you may find you melt the PVC insulation before shrinking the heatshrink. --John Rumm 17:08, 27 August 2007 (BST)

i notice there is no reference to joining multiple cables to multiple cables. Is this allowable, and if so, are there any special considerations re wire twisting that can make the join the best possible. (I have a particular problem where two 1mm squared appliance wires need to be joined to two 1mm squared appliance wires, and want to do the best job we can.)

You can join more than two wires in a crimp - just chose one large enough for the wire size. Heatshrinking can be harder obviously if you have only one extra cable (i.e. three way join) in that it will have to accommodate two cables on one end and only one on the other - so picking the right size can be more tricky. Alternatively use an enclosure like a chockbox. Twisting is not advisable since it makes it harder to insert the extra wires. Regarding appliance wires, it is not clear if you mean solid core cables (i.e. flat twin and earth) or flex. If the latter, than you really need a proper flex connector with cable grips to provide adequate restraint for the flex. These usually include screw connector blocks anyway, and hence crimping would not be appropriate. --John Rumm 06:34, 19 August 2009 (BST)

Jointing multiple wires: Is this a reliable method? I tried this with 3 2.5 T&E cables. To get 2 in required a yellow crimp which was too big for the one wire leaving. To compensate I folded the wire back and then crimped it. The joint did not hold under moderate force. Can this be done reliably? Steve

Its reliable if you can get a good mechanical crimp. I usually find you can (just) get two 2.5 T&E into a blue crimp, and that is solid. If using a yellow you may get a better result with all three wires in one end of it. --John Rumm 01:01, 2 December 2009 (UTC)
I just want to point out to everyone that you do not crimp single strand cable such as twin and earth as shown in article

crimps are for multi-strand cable. to join T&E some sort of screwed terminal block should be used. Dave Electrical Engineer.

Solid core / stranded

Hi Dave,
Thanks for the comment. As far as I am aware, the only time a crimped connection should not be used on solid core cable is when the terminal itself is explicitly marked as not being suitable for that particular cable type (i.e. a terminal marked for use on stranded wire only, should not be used on solid core). I have not been able to find any manufacturers of standard insulated crimp terminals that exclude use on solid core wire. Perhaps you could cite a reference for your claim?
Also may I draw your attention to Note 2 on section 526.2 of BS7671 (aka 17th edition the wiring regs), which states: "Terminals without the marking R (only rigid conductor), F (only flexible conductor), S or Sol (only solid conductor) are suitable for the connection of all types of conductors". (my emphasis)
In particular it is also worth noting that there are times (see 526.3 BS7671) where screw terminal connections are explicitly forbidden - in particular where a joint will be encapsulated or otherwise not available for inspection in future. Here the regulations are quite clear that allowable exceptions to the accessibility requirement include: "526.3 (iv) a joint made by welding, soldering, brazing or appropriate compression tool"
--John Rumm 16:37, 5 July 2010 (BST)