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

[viewer]

Looking at it from a different point of view...
The switches are burned but not the connectors nor the three individual "plug inlets".
I'd be looking for a common factor in these student houses and the one which springs to mind is cleaning. A good squirt with many cleaners will both corrode the contacts and create a track. Might be nothing wrong with the sockets.
Perhaps worth talking to the landlords - do they have a cleaner for the premises?
Either cleaner or students may be trying to de-grease the sockets and be over generous with the fluids.
Edit just read original post - "kettles" - again suggests fluid as condensate over/against socket.

 

[JohnW2]

Looking at it from a different point of view... The switches are burned but not the connectors nor the three individual "plug inlets". I'd be looking for a common factor in these student houses and the one which springs to mind is cleaning. A good squirt with many cleaners will both corrode the contacts and create a track. Might be nothing wrong with the sockets.

Possibly - I really don't know how readily a 'squirt'would be able to get to the switch contacts.

However, there are two things here, which may not necessarily go together all that often. We're being told that socket failures are particularly common in student houses. We have also been told/shown that, in this one particular case, it was the switch contacts (alone) which overheated - but I haven't clue as to how common that is in relation to the 'student house socket failures' in general.

I have to say that, in my limited experience, burning of just the switch contacts is pretty uncommon - the far more common situation (in my experience) being overheating/burning around the region of one or more of the plug pins / "plug inlets".

More generally, one imagines that, particularly in kitchens, sockets in any 'multiple occupancy' premises (not necessarily only students) probably get much more 'use' than in a standard one-family home. It's therefore possible that all is being seen is the effect of heavier use.

Kind Regards, John

 

[ban-all-sheds]

Plus maybe a bias towards electricians being used to replace dodgy sockets rather than homeowners DIYing. Or should that be DITing?

 

[JohnW2]

Plus maybe a bias towards electricians being used to replace dodgy sockets rather than homeowners DIYing. Or should that be DITing?

Yes, indeed - that's another very probable source of some bias in relation to what electricians see. I would hazard a guess that quite a high proportion of socket replacements in owner-occupied premises (but a much lower proportion in rented multi-occupancy accommodation) are DIYed (or whatever!).

Kind Regards, John

 

[ban-all-sheds]

... student houses ... cleaning ... students may be trying to de-grease the sockets ...

 

[martinxxxxxx]

... student houses ... cleaning ... students may be trying to de-grease the sockets ...

There mum's come down and attempt a clean up in order to recover HER deposit at the end of the let (in my experience) so it is not as far fetched as all that
But the students never clear up, apart from special occasions - when they are going to have a party etc. and they always complain about mice...

 

[Maxatoria]

When I worked for a Uni and used to visit the student digs to sort out access to the Uni's network I was always amazed when I could see 6-8 inches of travel adapters coming out of one socket especially when there was alot of foreign students as they'd all have their things connected 24x7 so there would be a spiders web of cables leading to all sorts of electrical appliances from across the world that were probably given to them to take for their studies but never bring back and would be illegal to sell in this country

 

[martinxxxxxx]

yes, but why only the live switch contact...

 

[JohnW2]

yes, but why only the live switch contact...

As JohnD suggested, if it was not due to dirt/damage at that particular pair of switch contacts, it might be explicable if the switch is designed for the L to break first and the switch had been used to interrupt high currents - thereby a risk of arc-induced damage (at just the L contacts), leading to subsequent high resistance contact and consequential overheating.

Kind Regards, John

 

[bernardgreen]

It doesn't matter which of Live or Neutral breaks first, the arc will be the same which ever breaks first as it is the same current that is being interrupted.

The voltage relative to earth has no affect.

The initial contact damage might be due to the contact switching ON when items with high inrush currents are plugged in with their own switch ON.

It is not good practice to use the 13 amp socket switch as the On-Off switch for appliances. But since when did students ever know about good practise

 

[martinxxxxxx]

I understand that, but the toaster and the kettle are hardly ever controlled by the wall switch.
I don't think the arrangement has a break first on live.
The dirt on the contacts is not a convincing argument.
I think that there is a not enough copper for the duty and the contacts are warping open and randomly it s the live that has opened up more and caused a high resistance contact.
But there isn't any way of proving this - well apart from RF 's rig. I can't wait to see what that reveals.

 

[JohnW2]

It doesn't matter which of Live or Neutral breaks first, the arc will be the same which ever breaks first as it is the same current that is being interrupted.

That depends entirely upon the duration of the arcing. If it is over before the Neutral contacts break, the current they are breaking will not be 'the same' - it will be zero.

It is not good practice to use the 13 amp socket switch as the On-Off switch for appliances.

Indeed - as I wrote, I tend to shudder silently whenever I see someone do that with a high load.

But since when did students ever know about good practise

I must say I would have suspected that youngsters would tend to not use the switches on sockets - probably more likely to just pull the plug out! Also, I do think that 'students' are getting an unnecessarily bad press in this thread - I suspect that, in the sort of contexts we're discussing, they are no 'worse' (maybe actually 'better') than any groups of people in shared, rented, houses.

Kind Regards, John

 

[plugwash]

Also remember a lot of students are foreign and only living here for a relatively short time. I suspect such people are far more likely than the general population to open the shutters with a screwdriver and force a german of french plug in and/or use dodgy travel adaptors that don't meet british standards for pin size/shape.

 

[SUNRAY]

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 a landlord myself, I have 2 rules about what WILL NOT be installed in my properties:
1) Flexible hoses on the sinks etc.
2) MK sockets.
Both are far too troublesome.

Edit: I didn't realise this was an old thread when I started the reply.

 

[securespark]

It doesn't matter which of Live or Neutral breaks first, the arc will be the same which ever breaks first as it is the same current that is being interrupted.

MK say that in their DP socket switches, the neutral makes first and breaks last, making it safer.