En el artículo , MM escribió:
Realistically, no one is going to do that for domestic 13A plugs and sockets, are they, though?
Me neither (although I have seen them elsewhere, e.g. in PCB-mount terminal strips). The closest equivalent is the MK Safetyplug which, as another poster said, has a washer around the fixing nut so it clamps the wire end without adding any twisting stress.
The thing about 13A 3-pin plugs having tongues is just D i m 's usual bollocks.
Quite. And that may be the difference between those who can (and have done so successfully for many many years) and those who end up with stuff melted. ;-)
It seems to work eh. Can you *ever* remember having a problem after wiring something using that process?
And, (if not under tightening or using a torque wrench) there is a definite 'feel' to this sort of thing that is easy to assume with others.
Indeed. ;-)
A couple of times I've assisted people (over the phone) doing what I would consider very basic tasks (like torquing down a cylinder head or replacing an alternator) that have ended in tears (for them, not me) because they don't have 'the feel'. The two instances I am thinking of, one incorrectly read the torque wrench and the engine stud snapped before the wrench clicked (when those with the feel might have suspected something wasn't right) and similar with the guy changing the alternator, stripping the thread on the tension bracket.
In fact, I've nearly stopped asking / allowing people to help me do stuff because of how often something get's lost or broken (of mine) whilst they are doing so, or just not doing it to my standards.
I was with BT 5 years and when I left my apprenticeship - soldering test piece was still in the display cabinet as no one else had managed
100/100 whilst I was there. I found it quite easy whilst others obviously struggled ... like I would if I was plastering a wall or trying to program to fix something on Linux (or any other OS of course). Everyone to their own etc. ;-)Cheers, T i m
You dont listen or think, do you?
I corrected your misinformation, particularly as it is well known to be dangerous. I see lots of people have done that too.
No. Not in 50 years.
Novices don't have that 'feel'. You learn the hard way by stripping a few threads first.
MM
No, you simply went along with misguided thinking that was wrong, and dangerous, and didn't listen to or even try and understand the arguments as to why it was misguided.
I'd ask those who tin the ends of the leads what current they are taking from the circuit?
It's often thin wires which would be easier to fit if tinned. So if only a couple of amps at peak, less likely to give trouble regardless.
What would happen at the maximum continuous rating - ie 13 amps - would be interesting. Even some factory fit moulded plugs will get warm or even hot at full load.
Quite, so we are obviously doing something right or 'different' to those who seem to have issues.
Good point and something I'd not thought of doing till you said that when teaching someone how tight to do up something [1]. Easy to get some sacrificial nuts and bolts in the vise and let them see just how little torque you sometimes need to strip / shear something.
Cheers, T i m
[1] As a support rather than design 'engineer', most of my efforts would be based around how to do, rather than not do something. eg, It would be 'how to tighten cylinder head bolts in sequence and stages', rather than to purposefully do it wrong and damage something. This is generally because I'm generally helping someone repair something they want or need, or allowing them to learn on my stuff, rather than just showing them *how* to do it as such.
Except, I never suggested any 13A plug had such a thing, just that I would like the option as I think they are a good idea.
But, trust Tomlinson not to be even able to get the story straight (and couldn't if he tried, he's not wired that way). I'm not surprised he can't though, one of the pitfalls of being a killfiling coward is you can't guarantee to get the whole / correct story. Not that things like the truth or (real-world) facts ever stopped him for making up his own story of course. ;-(
Hey, and if a 13A plug terminal did have a tongue, even he might be able to wire one up properly!!!
Cheers, T i m
The problem is that as an individual you are unlikely to notice any problems, even if you do ten a day for 50 years the failure rate is low enough that you wouldn't notice. However when you have millions of joints you will notice the problem. Conversely if there are millions of people doing it then some of them will have problems.
Ok.
But there is a good chance that those that have problems *because* they weren't *correctly* tinned over those joints made without tinning could be tending towards nill.
Yes, especially the incompetent ones (like Tomlinson, as he has shown us himself in this very thread!). ;-)
Cheers, T i m
They could but industry says they aren't.
I'd agree that it would be more typical that *I* would generally tin (and fold and tin) finer wires, simply to hold them together and have a better chance for the screw to have something to bite down on than I might on heaver / less stranded wire.
I think if properly tinned (eg, not 'over ' soldered) and tightened correctly / sufficiently then nothing.
They can indeed and here is one I saw earlier. ;-
Mate had his compressor plugged into a rubber trailing socket that was previously wired directly into the previous (higher power) compressor.
The fuse had gone a couple of times recently so because it was connected to it's own MCB someone though a solution would be some silver foil round the fuse. ;-(
I think a combination of a poor quality moulded plug (in comparison with an MK one) and plugged into a rubber trailing socket (even a branded one) allowed localised heating and potentially further stress on the fuse.
To help them isolate the fault, I checked it wasn't seized, that the caps were ok and after replacing the plug, that the motor ran ok on it's own. I then connected it back up and let it run up to full pressure and the plug was still cold (probably helped by being plugged into a decent Metalclad socket).
I've suggested they get the plug replaced with a decent (MK) one and a decent Metalclad socket fitted to the wall beside the compressor.
Cheers, T i m
What industry regularly tins the sort of joints we are talking about then, for you to get this data?
No one is saying (especially me) that tinning stranded wires is recommended, potentially outside harsh / marine environments in an effort to prevent corrosion to the exposed wires.
However, what I am saying is I have no experience of any stranded wires I have tinned and used in mains plug type applications have ever been an issue.
I am (fully) aware of the issues tinning a stranded cable (in an effort to make it more manageable, to resist corrosion or make it offer more material for some screw terminals to grip) like stiffening of the (previously more flexible) 'flex' and it therefore requiring more support than it might otherwise.
Point. If you take a bundle of stranded cable and 'tin' them (not over solder them), and trap them in a receptacle and clamp them in place, even if the solder is more malleable than the copper, where does the copper go? The copper may move within the solder *until* it's all touching each other strand, just as it would if there had been no solder there in the first place.
It's quite possible that a tinned wire may resist strands moving and therefore maintain a *better* overall tension / connection than an untinned one?
Cheers, T i m
That is exactly the point it does as you say. The problem is it doesn't do it instantly as you tighten the screw. It happens over the following month/years as the solder creeps out of the joint. The result is the joint becomes looser and the resistance goes up. This increases the heating and things go down hill from there.
Not a chance with normal solder.
Good, then there shouldn't be a problem. ;-)
Then I suggest you aren't tightening the screw correctly sufficiently.
The solder has no where to go as the copper wires are already pressed up against each other as tight as they can.
It can't because there is nowhere for the copper wires to go and what's more, the gaps between them are filled with solder, unlike a non-tinned cable.
Yes, if would, if your theory was correct.
Please explain how (as TNP suggested), tinning a group of cable strands can make the copper less stable than it was originally.
Ok, take a bundle of sticks, pull them tightly together and then wrap some putty round them. Put a Jubilee clip over the putty and do it up till the clip forces out all the surplus putty and pulls the sticks tightly together. How is that going to be any less tight than a bundle clamped up without the putty (if tightened up sufficiently / properly)? How is it going to be as tight (a bundle) as one supported by the putty in the gaps that the sticks could otherwise move into (had it not been for the putty)?
Cheers, T i m
That's nothing! I well remember a class at Maidstone Technical College, where we apprentices attended one day and two evenings a week, when we were introduced to the wondrous torque wrench (cue witty remarks). One lad still managed to strip a thread. The lecturer asked, did you not adjust the torque wrench correctly? Yes, he murmured, but I didn't think that was tight enough. Dunno whether he passed his City & Guilds later...
When I worked in the prototype department at Ford-Werke in Cologne, building the first Granadas, Cortinas, Escorts and Capris in protototype form long before production started, we had to use a torque wrench for practically everything. AND we had to paint a little stripe down the side of the bolt/nut with bright yellow paint so that the engineers/designers could see whether one had moved during 100 laps around the test track in Lommel. (Cologne-Merkenich had its own small test track as well.)
How many times have I watched novices tighten bolts or nuts holding a flange and observed how they frequently tighten ONE nut up tight, then the NEXT nut up tight, and so on. When I point out that the correct way is to pinch down the flange as evenly as possible, tightening each nut/bolt a little at a time, they think I'm nit-picking. There are probably hundreds of thousands of owner-"maintained" motor vehicles on the roads with dodgy practices like this built in, as if the original designers didn't know better than Bert next door.
MM
I really don't think any one person could ever achieve "millions of joints" in a lifetime. Aren't you getting a little bit carried away?
MM
Ha, industry once used "inflammable" as "not flammable"!
MM
The reason for not tinning is that it is cheaper in production. Either tinned, untinned, sleeved or crimped joints can give problems in mass production. Particularly with crimped joints, you are at the mercy of the crimp material hardness and the behaviour of the copper wire being crimped, which will have a variety of ductile behaviour. The auto industry suffers badly from poor crimp quality, particularly when it is done in third world countries. Mercedes went through a very bad period some 10 years ago on their ML product line. Military crimped connections are always IME tested for strength before being mounted in the equipment. Consumer products are pot luck!
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.