Why don't cheap sockets handle over 5amp with photos

[JohnW2]

Why do you say that? Surely the little 'blobs' in the switch which make contact are the weakest parts (smallest points of contact under proper usage) of the socket.
Edit - having reread your reply, you seem to be agreeing with me.
Why, then, is this damage inconsistent with my point?

Primarily because (unless you're postualting a simultaneous L-E fault, which would be stretching things!!) if an excessive current goes through the 'blobs' of the L switch contacts, the same excessive current should go through the 'blobs' of the N switch contacts. If thermal damage is restricted to the L ones, that strongly suggests that there is a specific problem of contact of those contacts - not just an excessive current, per se. Doesn't that make sense?

Kind Regards, John

 

[JohnW2]

these student-tenanted houses you keep going to, do you generally find that have been provided with good quality electrical accessories? or are the landlords penny-pinching cheapskates?

As I keep saying,one can't really blame landlords. Whilst you're implying (and most people would agree) that there are 'poor quality' electrical accessories, even the cheap ones are nevertheless meant to be 'of adequate quality', 'fit for purpose' and compliant with BS 1363 - in which case my finger points at BS 1363 and/or manufacturers, not the people who buy them 'in good faith'.

Kind Regards, John

 

[EFLImpudence]

Primarily because (unless you're postualting a simultaneous L-E fault, which would be stretching things!!) if an excessive current goes through the 'blobs' of the L switch contacts, the same excessive current should go through the 'blobs' of the N switch contacts. If thermal damage is restricted to the L ones, that strongly suggests that there is a specific problem of contact of those contacts - not just an excessive current, per se. Doesn't that make sense?

Yes, true.

I hadn't noticed it was both L ones.
Thinking it was just the one and presumably a bit 'weaker' than the N with perhaps 20A or more through it.

 

[JohnW2]

Doesn't that make sense?

Yes, true. I hadn't noticed it was both L ones.

I'm not so sure about that - it looks like only one of the L switch contacts to me.

Thinking it was just the one and presumably a bit 'weaker' than the N with perhaps 20A or more through it.

As above, I think that it probably is 'just the one' - but I would interpret that "bit 'weaker' " as meaning something 'wrong' (muck, low pressure, surface damage) to the L one. If, as you were postulating an excessive current (>>13A), being drawn due to the use of unfused (or 'nail-fused'!) adapters/extensions, were the problem, then I would expect to see thermal effects at both L and N contacts, wouldn't you?

Kind Regards, John

 

[martinxxxxxx]

these student-tenanted houses you keep going to, do you generally find that have been provided with good quality electrical accessories?

or are the landlords penny-pinching cheapskates?

No; the ones I go into are paying for my very expensive services . They have normally been ripped off by kitchen fitters that fit the cheapest sh1t that they can whilst charging top dollar. The electrical bit seems to be done at the lowest cost, personally I think you get what you pay for on accessories, but it is contractors who I blame.
It always surprises me how knowledgeable and savy even newbies on here are compared with the great general public when it comes to electrics. Even compared agianst professional landlords with multiple properties.

 

[JohnW2]

It always surprises me how knowledgeable and savy even newbies on here are compared with the great general public when it comes to electrics.

Probably true, but I stick to my point that the general public have every right to assume that anything which is 'allowed to be sold', particularly when underpinend by a British Standard, is 'fit for purpose'. Most of them do, of course, understand that, as with most other goods, there is a spectrum from 'economy' to 'premium', but they still probably assume (I would say, with reason) that even the cheapest are still 'fit for purpose'.

Kind Regards, John

 

[EFLImpudence]

I'm not so sure about that - it looks like only one of the L switch contacts to me.

On the metal parts, yes but the plastic looks like both, albeit not as bad.

If so, both Ls cannot be coincidence.

As above, I think that it probably is 'just the one' - but I would interpret that "bit 'weaker' " as meaning something 'wrong' (muck, low pressure, surface damage) to the L one. If, as you were postulating an excessive current (>>13A), being drawn due to the use of unfused (or 'nail-fused'!) adapters/extensions, were the problem, then I would expect to see thermal effects at both L and N contacts, wouldn't you?

Not if this was where their 'kettle and toaster' (or whatever) are permanently plugged.

 

[securespark]

these student-tenanted houses you keep going to, do you generally find that have been provided with good quality electrical accessories?

or are the landlords penny-pinching cheapskates?

If that's aimed at moi, then it's a real mix.

 

[JohnW2]

I'm not so sure about that - it looks like only one of the L switch contacts to me.

On the metal parts, yes but the plastic looks like both, albeit not as bad.

I'm very far from convinced - I think that's probably just soot tranfer onto the other one - and if it were due to locally generated heat (to the extent of burning plastic), there would surely be at least some sign of an effect on the metal (which looks 'pristine').

If so, both Ls cannot be coincidence.

If 'twere so, then I would agree with you - but, as above, I don't think it is so!

... If, as you were postulating an excessive current (>>13A), being drawn due to the use of unfused (or 'nail-fused'!) adapters/extensions, were the problem, then I would expect to see thermal effects at both L and N contacts, wouldn't you?

Not if this was where their 'kettle and toaster' (or whatever) are permanently plugged.

I don't understand - why would that only affect the L switch contacts?

Kind Regards, John

 

[EFLImpudence]

I don't understand - why would that only affect the L switch contacts?

Well, accepting that it is only the one, bearing in mind that this is just one example of a quoted frequent occurrence, I am not sure.

There was obviously more resistance, as you have said, at the L contact than the N.
Whether students get their L contacts dirtier than other people do is not likely even if the rest of the room is.

My original reply suggested that this contact was 'weaker' than the other.

I just thought that a manufacturing process requiring a definite minimum capacity of 13A may be unlikely to produce every part at 13.1A but may have a range which could, under overload, result in some being burnt and others not.

 

[JohnW2]

There was obviously more resistance, as you have said, at the L contact than the N. Whether students get their L contacts dirtier than other people do is not likely even if the rest of the room is.

Quite so - which is why I think that, in this case, the students are the last people whom any fingers can be pointed at!

My original reply suggested that this contact was 'weaker' than the other.

Indeed - and that is obviously true in some sense since, unless it had been caused by an L-E fault which wasn't cleared quickly by the fuse (or nail!), the L contacts clearly have suffered in a way which the N ones haven't.

I just thought that a manufacturing process requiring a definite minimum capacity of 13A may be unlikely to produce every part at 13.1A but may have a range which could, under overload, result in some being burnt and others not.

Undoubtedly true, although I doubt that anything would 'burn' at 13.1A, but not at 13.0A However, we're seeing quite serious heat generation at the L contacts and, as far as I can see, absolute no evidence at the corersponding N ones. I doubt that could be explained by the (inevitable) different CCCs of the two sets of contacts.

Kind Regards, John

 

[martinxxxxxx]

Maybe the fuseholder in the plug is getting hot and that heat is being conducted through the copper and causing the L contact to have a little more heat than the N contact thus lowering it's ccc. Say there was a 5A fuse fitted that was a little overloaded, this would produce the heat perhaps

 

[JohnW2]

Maybe the fuseholder in the plug is getting hot and that heat is being conducted through the copper and causing the L contact to have a little more heat than the N contact thus lowering it's ccc. Say there was a 5A fuse fitted that was a little overloaded, this would produce the heat perhaps

The thermal damage is obviously restricted to the L switch contacts, not the vicinity of the plug pin or the socket contact with the pin, so the pin cannot have been getting all that hot. I rather doubt that enough heat could be getting from the pin to the switch contacts to bring about a situation in which the current through the L (switch) contacts was enough to produce severe thermal damage, whilst there was absolutely no sign of overheating due to passage of the same current through the N ones. However, I guess that nothing is impossible!

Kind Regards, John

 

[EFLImpudence]

Undoubtedly true, although I doubt that anything would 'burn' at 13.1A, but not at 13.0A

No - wrong end of stick.

What I meant was - with a minimum requirement of 13A and an obviously cheap manufacturing process some of the parts (switch contacts) may actually be capable of carrying a maximum of 14A and some, say, 19A.

Consequently the product actually exceeds the minimum specifications but under a load of 19A only one contact would actually suffer damage.

 

[JohnD]

In some switchgear, L is supposed to break first and make last, so more likely to suffer arcing under load.

I don't know if those cheap socket switches would be designed to do the same.