Multi socket extension lead - interesting failure mode

[Chris B]

I have had a multi socket extension lead untouched behind the TV for I guess 5 to 7 years connected to the TV, DVD, Video and Blue Ray. It was a cheap unit, bought not off e-bay but from a high street store at the bottom end of the market. I would never have really expected it to cope with a 13A fan heater without getting hot but I thought it would be fine for the use it was going to be put to (and indeed it has been up to now).

Some tidying up following the final demise of the VHS Video player forced me to disturb it.

I never expected the failure mode as shown in the linked photo.

For info printed on the bottom was BLS114 BS1363A Total load not to exceed 13A

And a sticker which said 20070725 (Which I suspect is the date of manufacture).

[Chris B]

PS That link doesn't seem to work with my Edge browser but it seems to work in FF and opera.

[Huge]

[24 lines snipped]

[e-mail]

[Andy Burns]

Was it in sunlight where it has lived?

I don't normally use Edge, it does open it ok if rather small, but once you zoom in the image disappears above a certain size, then re-appears if you go to full-screen.

[Chris B]

No. Daylight yes but no direct sunlight.

[Martin Brown]

They are not supposed to fail by brittle fracture like that.

Are you sure it hasn't spent some time with a more aggressive load (like a kettle or vacuum cleaner) plugged in? I'd be amazed if the load that home entertainment kit presents could cause trouble unless you have 1kW loudspeakers or something.

Could be stress corrosion cracking from exposure to solvents or sunlight. Or that something very heavy was dropped on it in the past.

It is odd that both the plug and the socket have failed but there is no evidence of heating of the brass. I have seen seriously abused ones with discolouration and melting of the casing.

I reckon mechanical damage from a heavy falling object.

[Chris B]

No definitely not. It has led a very sheltered life on the floor behind the TV. The plug has been in the wall and the extension on the floor. It has, as someone else suggested gone brittle in exactly the way you would expect of a thin supermarket carrier bag exposed to sunlight. It probably doesn't show up on the photo but there are several other micro cracks which I suspect would fall apart with very little further provocation.

[Lobster]

On 19 Sep 2016, Chris B grunted:

164223098.jpg?

But it can't be coincidence that the plug top has disintegrated at the same time? Has to be impact, surely!

[Chris B]

You do realise that the plug top is at the end of a 0.5m cable (and was plugged into the wall). It has only been plugged into the board to make it more compact to photograph. If it was impact it would surely be the top of the plug rather than the bottom section.

If it was impact it was during manufacture/distribution and certainly didn't show up when I installed it.

[Graeme]

Ah! You're too subtle for some of us, Chris. I had not realised that the plug in view was the plug attached to the device.

[Scott]

So you have manipulated the evidence then! When you say a 'high street store at the bottom end of the market' I take it you mean Poundland *. I have found some products from that particular outlet to be complete rubbish and would certainly not buy any safety-critical item. I prefer to take electrical safety seriously.

• Other pound shops are available.

[T i m]

I wonder if there was something in that area that produced some sort of fume that affected the plastic like that (the fact that it's done both components even though separated)?

In (what could be) a similar vein, I recently dug out two pairs of new 'deck shoes' and the soles on all 4 shoes had become so brittle that they snapped rather than bend. ;-(

I must admit that I would go along with those thinking it could be sunlight ... if not direct, could it have been reflected?

Cheers, T i m

[Fredxxx]

The brass earthing strip looks distorted to me. Mechanical damage was my first thought.

[tabbypurr]

It certainly looks like the poundland product. Just bad plastic I assume.

NT

[Lee]

Had a similar issue with all the plastic mouldings in an LCD tv I took a look at. So brittle they fell apart at the slightest touch - but that had been installed a little too close to a log burner :) :)

[Adrian Caspersz]

I've seen insides of a few of these things, their brass strips don't exactly happen to be that straight. These things are after all mass produced.

Yup, crap cheese grade* plastic that doesn't take kindly to being stressed.

Possible the socket was forced apart by tension of the earth pin against the plastic due to close clearance, and the plug top either fractured when withdrawn from it's socket, or killed by an overtightened securing screw.

• Ice cream carton plastic? Is it possible to do a burn test to identify it?

[Scott M]

Had exactly that happen with two recently; both different (and one similar to yours IIRC) but brittle beyond measure. I wellied both against the wall and they exploded like glass bottles. They were a few years old and basically unused.

Crappy chinese plastic.

[Mike Tomlinson]

En el artículo , Huge escribió:

mailto: [e-mail]?Subject="Win10 sucks donkey dick"

[Brian Gaff]

Not much help to me. However since I cannot see the picture, one assumes its mechanical in some way. I had one fail recently where the connections to the live and neutral cannot be sprung back enough to keep good contact to the plugs. Thus the slightest wiggle makes it spark or go off on that socket. Now to me this seems like a design issue, but as you say its far too old now to expect anybody to sort it. To get the bus bars out and away to do a respring job would require melting plastic, so its a bin job. also the screw into the live wire has been done up so tightly its sheared off half the top of the screw, and so one would need a strong pair of mole grips to get it out. Made in England it says... Hmm. Should have bought Chinese. Brian

[Brian Gaff]

I hate edge with a passion. Firefox is far more reliable and its a real shame they hard coded edge into the search in windows 10. Brian