Your feedback on regulation issues

if we were really up to date and did not want things to work loose with vibration or thermal cycling, then meter tails in line RCDs and main switches would terminate with something like the Finger nippin good 125A wago 'top job' connectors

By better tails do you mean the 19 strand type? Do you find them more secure and yet still hold the bend to enter top terminals?

I wonder how many people cut the cable and then make the bend when the other way about is much more satisfactory?

I have a notion that the growth of EV charging points in domestic circumstances will begin to probe the robustness against overheating of both the plastic and metal consumer units, their onboard devices and their tails connections.

I note that one accreditation body has set assessments in their EV charging installation course where the candidate will be required to use a spare way in an existing consumer unit. Yes they will be expected to carefully assess the existing loading and may err well on the safe side during assessment but whether that carries into real installations is another matter. Commercial pressure can often squeeze good sense to death!

I cannot sling mud at anyone who was responsible for causing fire damage due to their installation methods. When E7 ruled here way back in the 1980s, I razed a good part of a National Trust property. It was due to a faulty swichfuse but you know how muck sticks! Things were made very much worse when a week later a loose neutral connection on a contactor caused a fire brigade call out to commercial premises that we had just equipped with E7 heating! I thought the good Lord was definitely against me when another neutral connection in a switchfuse failed and burned back insulation which set off the fire alarm in a block of flats. Needless to say my erstwhile cosy relationship with a firm of consultants was terminated fairly sharply. 

Ever since, my installations have been over-designed and checked thoroughly for appropriately secure connections.

Onsite crimping is not "dubious" in any way

I must have been unlucky to come across many dodgy crimps in domestic installs then - most usually "automotive " type crimps on solid core cables, usually applied with "plier" type crimping tool that come loose on a simple tug. If those doing that kind of thing can't be bothered to use the right type of crimp or buy a £25 ratchet crimper, what chance of persuading them to buy something that'll properly deal with 25mm²? Let alone insulating it properly (adhesive lined heat shrink?)

   - Andy.

Those are there due to the lousy standards of the bottom end of the industry Andy. Unskilled and unknowledgeable hardly cover it. Those plier type tools do not make satisfactory crimps ever, even of fine stranded wire, because the "dies" are the wrong shape and the force inadequate. The range of crimps you are talking about is used in many places, appliances included, but rarely as original equipment in cars, because they don't do well in rough environments. We do keep finding wires extended during CU changes using them, and they usually attract a code C2 from me unless they are properly made with the correct tool. Earth extensions are particularly bad! I think that the crimp extension I illustrated above would make a significant improvement to installation time, and even more in fire safety. It is certainly better gripped by the terminals then even 19 strand tails cable, and one rarely finds the busbar connections loose of a similar construction. I would reckon that 50 jobs of CU change would save the crimp tool price in saved time and reduced frustration alone.

Why don't they look at changing the cable type for tails. 25mm Tri-rated style cable is far easier to terminate and clamps up nicely in the terminals on switches. Obviously they are not double insulated, but if they were it would stop alot of loose cable issues we get with tails