I was thinking something similar as that heat damage was on the surface of the socket and clearly not conducted from below as there was no melting that side. The whole video is mysterious like that. There's nothing obviously wrong with the socket construction, and it's almost like somebody has plugged in something with a much higher current load than the socket was rated for. An old-fashioned unfused multi-way adapter would do it or something where the 13A fuse had been replaced by something else.
@@TheEulerID first one taken apart, how about its simply contacts that are poor causing the heat? look at the bars and there discolouration, that was no way from an external source. 2nd socket left side yeah i agree it looks external and also it doesnt show the same 'burned' bars so i think your spot on with the 2nd one, i think first one probably spent its whole life with a kettle in it. I'm sure those sockets are the same as the six i bought i bought from b&q when they dumped them off at 50p each....gonna be keeping my eye on them...
Lots of crap plugs roaming around these days so wouldn't surprise me. @lez briddon That's always a red flag, I bought some LED's that were being sold off at similar prices thinking I got a bargain. Turns out they have a really high failure rate.
Yeah me too - but the switches aren't required by the standards, certainly you can buy unswitched sockets and afaik always have been able to. presumably the maintainers of the standards think it's perfectly acceptable to be routinely making/breaking currents of up to 13A on the pins...
@@joinedupjon I don't know if switched sockets appeared the same time as unswitched or if unswitched came first. I only have switched sockets, wouldn't want the unswitched for that reason.
You should turn the appliance off with its built-in switch, then unplug it. Heaters have massive switches. This puny thing is bound to fail; best if they didn't include it at all.
Specified unswitched sockets in my last house. Annoyed the electrician- I think he intended 'acquiring' them... I do not plug/unplug- I switch off the appliance by its switch. Why unswitched? To stop people switching them off at the socket meaning I had to check where, and walk to the socket. A function should only have one control (unless either will work- not require both).
@@joinedupjon Unswitched sockets have their uses, they're particularly useful for appliances under kitchen counters with isolators above & for loads like freezers which you don't want people switching off.
I have found that if the plastering on the wall isn't level, over-tightening the faceplate can crack it. Thermosetting plastic is quite brittle and won't bend around unlevel plastering. It looks to me that the switch on the faceplate has been used to turn on and off a high current device, rather than using the switch on the device itself. That's going to cause arcing and it will fail eventually. And the arcing at the plug pins shows that the load was switched on when inserting the plug. The sockets may be cheap, but I think they have been abused somewhat too.
@John GB ... if that were the case, then screwdrivers would be made as sharp as chisels and as strong as crowbars. Screwdrivers don't come with instructions telling you what not to do, but if you want them to last you don't abuse them. You wouldnt drive a car to its maximum all day every day and expect it to last a long time. These sockets were surely certified, if not, the owner shouldn't have installed them. However the sockets are cheap, that's why the owner chose them over a quality brand. They would probably be ok for 'normal' use, but these have been clearly abused. If the owner wanted to give them some heavy duty use then he should have gone for a quality brand.
@John GB ... and there you have it. "If the design is cheap or wrong they won't be given the bs en number". You cant have this both ways. If the design was poor, then they would not have been certified. If the design was good then they wouldnt have failed from just having a 13A appliance plugged in. Yet they did fail. Who knows the state of the appliance! Was it overloading? Did they bypass the fuse with foil? Were they plugging it in on full load and allowing the pins to arc? Yes to that last one! They may well have made the bs grade, but they were still cheap, that's why the owner bought them, and had little regard for the strain he was subjecting them to. ...a car will pass its MOT but still won't stand up to you thrashing it. The sockets have been thrashed. Don't continually use the insertion of the plug as a switch for your 3kw load, don't continually use the switch on the socket to switch your 3kw load, don't continually do 0-60s in your car. If you do, don't expect these things to last too long. And that's what we see here.
I agree. All you needed was cables badly arranged in a shallow box to end up stressing the front plates and causing them to crack. There is no sign of thermal damage of the front plates causing the cracks. Looks like a poor installation and very rough use, and I am surprised they lasted as long as they did.
So what's your conclusion John? Don't plug 2kW loads in to cheap sockets? All socket outlets are pretty cheap these days including MK and Crabtree. BS 1363-2, it's a bit of a surprise when you look at the standard and realise the current rating isn't 13A x 2 for a double switched socket outlet!
Chinese made rubbish ., MK have moved firstly to wales from Edmonton then i think to eastern Europe and they are getting poorer in quality and quality control
MK mark various products as 'Made in Malaysia' now. I've had one or two accessories fail in eight years of fitting them almost exclusively. Still considering going elsewhere though; their CU's never have enough earth terminals, there is no sign of them making compact or Type A RCBO's and frankly their website and lack of online engagement make it look like they're stuck in 2001. I now understand they're discontinuing Duraplug, though to what extent is uncertain. I sometimes wonder if they're only bothered about huge companies using their products
That last one with burnt socket connections, looks like the fault could be with the plug pins that were pushed into it. The plug may have had corroded and dirty pins. With a large current draw on, say a heater, would cause heat and arcing through dirty pins.
They look like pretty okay socket outlets as they go, not great, but not bad. It does look like the issues stem from the possibly filthy pins on whatever was plugged into them looking at the shmoo on the contacts, I dunno,
I wonder if these were just made horribly poorly or perhaps they experienced some vibration which caused constant arcing due to insufficient contact pressure to begin with? Maybe the insides vibrate with the 50 Hz current and cause constant sparks?
My mother has dementia and is in her 90s. She has been doing exactly this. Moving a 50 year old electric fire from room to room desperately trying to burn the house down. All she has done is wreck multiple sockets.
5 років тому
@@mbaker335 Not very nice dementia, when my mother in law got it she burnt an electric kettle by putting it on a gas stove, her brain went back to when she was young. She could remember things that happened 50 years ago but not what happened yesterday.
seen the second one before, had a dodgy cheap USB PSU plugged in, complete with C mark on the back, they did not even manage to fake the E to go with it, those things can get extremely hot and sometimes go boom.
They were not exactly the solidest construction, the front sounded rather brittle and probably did not provide much support for the switches. Another possibility is that the electrician did not put the junction box flush with the surface of the wall, or over-tightened the screws, putting strain on the white front. Seem to be a product from the land of Ping-Pong Charlie.
I bought hundreds of cheapo sockets from screwfix many years ago. They failed in the switches pretty quickly. Cost a fortune in fuel and time going back to all the customers houses replacing them over the next 12 months. Never installed crappy sockets or switches since, it's false economy. I used to swear by mk but started to see quality issues with them too over the past 15 years or so.
The fuse is in the plug not the socket. The idea being that the device is fused to what it's rated capacity is, however far too often 13a fuse is supplied as standard with devices. I tend to replace my fuses to the correct one, though I doubt most people bother. It's a nice extra protection to have and can protect the device not just the user.
Those things you called shutters, what are they for? I got an orange extension socket that wouldn’t work. I took it apart again and the red ‘T’ shaped shutter thing seemed to prevent a connection between the 3 pins of the plug and the bits the pins go into, so I took the shutter out and discarded it. The extension socket now works. I don’t see what good the shutter does.
It actually looks like the heat expansion of the ground pins of the plugs caused the sockets to crack. Even if it goes no current in ground normally, the heat of the live and neutral busbars inside the socket, might have transferred heat to the ground pin and/or ground busbars via heat conduction and/or heat radiation, why the ground pin enlarges and splits the socket. Since these sockets are made out of a "stiff" plastic which are also a bit fragile and brittle (like bakelite, ceramic or glass), any stress inside the ground pin hole, would crack it. Normal socket plastic are atleast a little bit elastic. The live and neutral pins are jacketed, why the heat expansion of the lead inside the jacket, just leads to a slight melt of the plastic jacket from the inside, and of course the plastic of the jacket itself can compress a bit to give way for the heat expanding lead, and when the plug pins have cooled off again, they can be pulled out without problem. (the contact part of the live and neutral pin of course enlargens, but when they do, they are already inside the socket)
In the UK, all the plastic wall plates are this brittle material, urea formaldehyde, because it is thermoset and won't melt. I guess most sockets just have a bit more clearance around the ground pin
@@johncoops6897 eeh? The ground pin is made of metal. What happens when you heat up metal? Even if its a very little expansion, like on the micrometer scale, if the clearance is too small in the socket (transistion clearance), it would of course split the socket when it heats up. I checked the thermal expansion coefficient for Yellow Brass with Copper Base (C27000), and it has a thermal expansion of 0,0203 mm per *C . It means that if it would heat up 10 degree, from 25 to 35 degree, a 1 meter piece would enlarge 0,2 mm . A ground pin is roughtly a cm on its longest part, so it would be 0,2 mm divided by 100, which is 0,002 mm Its very small, its 2 micrometers. Since we saw discolorations on the busbars, we are talking about temperatures way above that, even above like 150*C-200*C. If we then imagine that this heat might have transferred to the ground pin via radiation and/or heat conduction, lets say that 100*C was transferred, thats 0,02 mm in heat expansion.
@@sebastiannielsen - Sorry, but despite your hypothesising that is simply not the most common way that these kinds of cracks form. Even if the pin did expand by 0.02mm that is still under 1/10 of the allowed height dimensional tolerance (7.8 to 8.05 = 0.25mm) plus there is additional tolerance in the size of the hole too. Examination of the video at 16:33 shows that the cracks are from top and bottom of the earth hole, so you'd have to base your assumptions on expansion in WIDTH of the earth pin, nominally 4mm. So if there really was a 100°C rise, we are talking about 8 um (MICROmeters) or 0.008mm expansion of the earth pin. That is simply irrelevant in the scope of this application.
Notice the excessive amount of grease on one of these switches. I wonder if the copper is actually copper or brass. The construction of the switches seems to be not very good; not making proper contact due a lack of pressure, perhaps. That would heat up nicely.
@Meghnad (Who roars like thunder behind the clouds)I wasn't clear; I meant to say some inferior alloy (brass or copper colored or coated) instead of real brass or copper. I don't know about the excessive grease: it may become conductive over time? Not sure. At least it looks rather sloppy. I agree that the implementation of the mechanical design seems to be poor, possibly causing bad contacts and, hence, arcing.
@David Parry yes maybe but you would not normally expect a so called reputable retailer do sell this rubbish, and just goes to show that a BS number means nothing, and should stand for bull shit
I'm inclined to suspect that it was the same heater used in both sockets and that the plug was overheating. Because I've seen a case where somebody acquired a second-hand heater where the live connection in the plug was loose, leading to overheating and damage to the socket. So he moved it to another socket. And then another socket. And blamed the crap sockets for being defective. The second-hand heater had come from his landlord. Who pointed to the burned socket where it used to be plugged in, blaming the socket for being defective. SMFH. As for the mysterious arcing on the fluorescent, I have to wonder if there's a kid in the house. A kid in the house who sticks wire across the live and neutral pins of the socket then flicks the switch on and off quickly. Maybe even rides the balance-point of the switch to prolong the arc. Great fun!
This is a poor design, each of the two sockets has four low pressure "brass" metal-to-metal contacts carrying the load current in addition to the actual switch contacts and the contacts with the plug pins. Lots of extra contact resistance and therefore heat dissipation.
John are double sockets actually rated for 2x 13 amp loads plugged into them. I remember seeing a double plug assembly so you could get 16 amp out of a twin socket, I think it came with a welding set. , I would assume that’s a bad idea as the current share could not be guaranteed. Regards Chris
Average Joe yes this thing looked like two moulded plugs bolted to a cross bar. I think the idea was meant to be you could only plug them in to a dual socket together thus you couldn’t put just one plug in and have live pins on the other plug. I guess it would have been unsafe on a raised socket. I think they were being sold with welding sets or perhaps a pressure washer. I don’t remember it was 20 years ago. I kind of like the idea if I could get a 16 amp industrial socket to run my plasma cutter at it’s rated 16 amps rather the just turning the ampere down a bit. Kind of arbitrary for me anyway as the garage is run from a 13 amp fused spur. Still working better now i replaced the fuse with a nail. NO I DID NOT replace the fuse with a nail, it was a wood screw. NO I didn’t do that either LOL.
BS1363 has a test for sockets which is 14A in one and 6A in the other, and after a certain number of hours the temperature must not exceed a certain value. So 20A total in theory, if the socket complies with BS1363 - which of course they all should. However there is nothing to stop manufacturers making their sockets better than the standard, so at worst it's 20A, and at best it could be a lot more than that. In any event, a 2kW heater should not cause overheating to the point of cracking things.
MK, Crabtree, Schneider practically never fail, with electricians charging - entirely reasonably £100+ to just walk through the door I have no idea why anyone cheaps out on this stuff, presumably ignorance.
www.m2electrical.co.uk/ Still sold, as far as I can see:- www.m2electrical.co.uk/index.php/wiring-accessories/soft-edge/softedge-sockets/13a-dp-2-gang-double-switched-socket-white.html
additionally, there's a possibility that the plug top has poor connectivity.?? i have experienced before a poor moulded plug top. never experienced myself any issues with M2, but i do now only use Hager brand, never any issues to date.
@David Parry current-cy . . .that was a good one. . and good guess for i am a samsung user. . .our solution is to shake our heads, say ohm dear . . and just go to the pub anyway
British plugs and sockets are lame....whats with the on/off switches....just another connection point that when weak leads to overheating....and added fire hazard.
Well made British sockets are safe and capable of giving many years of reliable service. The switch isolates the appliance which is far safer than having live leads trailing all over the place. Problems arise when cheap knockoffs get onto the market. Same issue with car parts.
Video on that is underway, available soon. However the quick summary - doesn't matter, purely personal choice whether double or single pole. Or have sockets with no switch at all.
Are those ground holes large enough? The plates look like they were split by forcing an oversized ground pin into the sockets. Odd that the contacts on the first one didn't appear to have had any arcing. Also, i'd expect to see some discoloration in the plastic if the thing overheated. It's a bit odd to see the neutral switched in parallel to the hot. That's not standard practice in the US.
Thumbs up for this video J.W. I had my double socket replaced by my council and they were baffled as to why it cracked. The sockets were made by Crabtree and they've replaced it with another Crabtree. My 2Kw heater factory fitted plug was deteriorating ie the fuse cover was starting to melt so I cut that off and replaced it with a BS 1363 13AMP 250V plug top and there's been no heat since. Must be the factory fitted heater plug that was causing the problem.
yes the major issue with heaters is the flex near the plug, it gets stressed and causes a high resistance, cut a few inches off and new plug sorts them
For second socket taken apart the heat mark is where the fuse is in the plug so maybe the fuse was loaded to it's rating and caused the heat mark on the socket?
Interesting dissection! Is there a chance that a failing appliance that was drawing excessive current but not enough to blow its plug-fuse, spent time connected to the cracked plate units and went full-fault on the 'welded' plate?
John, I recall from one of your previous multimeter reviews lately that you did not recommend using a Cat 1 meter. That being the case. I checked my one, which has never been used incidentally, to find that it is a Cat 2. Can this be used for household mains testing? This is a "Lidl" product and of German manufacture.
There isn't anything wrong with any of the categories, it's more to do with what things are suitable to be used for. Cat I are only intended for use on electronics, low energy devices that are not connected to mains power. Cat II are ok for testing appliances and other items connected to mains voltage circuits. They are not suitable for testing the actual wiring installation, consumer units and similar, which would normally be a Cat III, or Cat IV for the actual electrical supply.
@@jwflame Many thanks, John, for the prompt reply. However, I've since checked the market and find that, for example, the Fluke range is expensive for the amateur so I'll need to purchase a cheaper Cat 111!
At 9:55, it looks like both the live and neutral switch contacts were arcing and appeared like they could be pitting. Once the contact surface was compromised, it was probably starting to overheat, even on light loads. The owner might even have swapped the high current load and usb charger on the different sockets over the years and the USB damage was the final straw. Could be a design fault if they used a cheap alloy that couldn’t survive too many surge current contact closures.
John, some of the cheapo electronic ballasts (my guess is fish tank lighting in this case) don't have NTC inrush limiting thermistors, so this arcing and welding does happen, more so with substandard switches. The plug has obviously been inserted with the switch ON in both sides of this socket, the inrush blowing little chunks of metal off both the plug and contact at the point of contact. Also there won't have been the desired "snap action" when inserting the plug.
Looking at the switches, there appears to be very little contact area between the busbars and the moving switch contacts, that certainly could be a reason for the switch overheating.
So what’s the science behind overheated loose connection? Is it the arcing that creates the heat or the fact that the high resistance connection acts like another resistive load thus drawing more current? I’m a bit confused here. Thanks
Probably both... the first (bad contacts) creating arcing & heating, and that caused the second issue (soot, pitting and increased resistance) which compounded matters... things spiral downward quickly from there.
If you have high contact resistance then that is in series with the load, so the total current draw is actually slightly less. The problem is the contact resistance dissipates significant power when current flows through it and gets hot. Power is current squared times resistance. For a 2kW heater the current is about 8A. So even a resistance of 16 milliohms will dissipate 1W and that will generate significant heat in a small contact.
It appears the switches are the weak point in these sockets, I wonder if it's a common issue of the design or more specific to some manufacturers/models of sockets
this is a cheap knock off, the design itself is fine, but a bad copy with poor materials, such as if the switch end melts under heat it puts less pressure on the switch and causes more heat and fails, if they used an inferior copy of the materials
You would be shocked at the amount of am small hours we on the conspiracy exposure side of things have to put in due to the censorship levels we have to endure, all thanks to the monopoly control of the Terrorvision and all MSM.
Or maybe he just set the upload to start and the system published it for him after the upload finished? I'm not sure how it works since I'm not a producer though.
Unless the appliances were at fault, the sockets were only supplying 8 amps. If the load of the appliance had exceeded 13 amps, the plug fuse should have blown.
@@alanpatterson2384 If you had 13A fuse in the fuseboard, the cable and socket could not be overloaded. Its very easy to overload the socket the way your installing it, just put two 13A loads in to a socket like this and you will excide it with 100%
There are two lots of wire between the breaker and the socket, and the fuse in the plug will stop the current when it blows. BS1363 specifies fault conditions the socket outlet must survive.
Morten Winsløw so how do you suggest we wire the fifty plus outlets in my house? Fifty individual circuits? Stupid. We have some of the safest electrical standards in the world.
@@MrSwanley yes but the expansion and contraction are easily absorbed by the large frame but I did have cracking there when the house was new now filled .
Polycarbonate is an odd material, as it is really flexible yet will develop cracks if it is stressed for long periods. A crack like those in the power outlet could actually be caused by the plug having incorrect pin spacing or being bent. *EDIT* Please ignore that... I was unaware that Britain still uses a "bakelite" type brittle plastic for these covers. The rest of the world made that material non-compliant a LONG time ago, because itso easily cracks and reduces electrical safety.
john ward would you please stop mumbling when you speek and form your words correctly. Have you ever watched your own videos please do so you will then understand what i mean. This is not meant as a insult please don't take it as one it is constructive advice. good videos
Gee, the mandatory 13A HRC fuse in the plug didn't do a bloody thing to prevent the over-current failures on the second socket. BTW - those faults don't look like they could possibly be caused by a 2x54W T5 fluorescent. Looks like a large inrush current load without a separate switch has been controlled on and off via the socket switches.... when they failed, then the user just plugged the load in, causing arcing of the plug pin contacts.
16:20 - re: the cracks of faceplates, it is very odd that this is attributed to overheating. I'm in Australia and brittle materials like UF are no longer used here. I've quickly reviewed BS1363-1 and -2 and I cannot see any requirement to use "thermoset" plastics, let alone brittle UF etc. The standard requires that materials must pass tumble barrel and other mechanical testing, plus material is NOT required to be "fireproof" but simply to be self-extinguishing (
When it comes to my HiFi separates I polish all the plug pins each year with brasso and zero grade wire wool, dirty pins and poor contacts cause issues when you try to pull a decent amount of current.
Bizzare failures. Why not.. before any dismantling, shove many amps (13) through the socket and do an overall socket resistance and power loss calculation. You could leave it on and see if it gets worse..thermal runaway..? These things should have a contact resistance spec, but I've never seen one
@@westwonic I didn't😃when it started to break my brain ,I turned off and expressed my concerns. Have you been practicing,your S's ,R's & T's? I learnt mine years ago, good luck
8:37
JW : we will just bend that a little bit. .
KEERRRRUUUUNNNCCHHH
JW underestimates his strength AGAIN
*socket faceplate has left the chat*
Whiteboard marker over the crack and then wipe the excess off would have shown up the crack without making it worse.
looks like there is more to this story 3 sockets from same guy failed with light loads emmm
Isn’t that mystery hot spot on the front exactly where the plug fuse would be in a rewireable plug?
I was thinking something similar as that heat damage was on the surface of the socket and clearly not conducted from below as there was no melting that side.
The whole video is mysterious like that. There's nothing obviously wrong with the socket construction, and it's almost like somebody has plugged in something with a much higher current load than the socket was rated for. An old-fashioned unfused multi-way adapter would do it or something where the 13A fuse had been replaced by something else.
@@TheEulerID first one taken apart, how about its simply contacts that are poor causing the heat? look at the bars and there discolouration, that was no way from an external source. 2nd socket left side yeah i agree it looks external and also it doesnt show the same 'burned' bars so i think your spot on with the 2nd one, i think first one probably spent its whole life with a kettle in it.
I'm sure those sockets are the same as the six i bought i bought from b&q when they dumped them off at 50p each....gonna be keeping my eye on them...
Bryn Jones I remember as a teenager having a fuse blow in a plug, with an external fuse cover. It blasted a divet on the socket faceplate.
Lots of crap plugs roaming around these days so wouldn't surprise me.
@lez briddon That's always a red flag, I bought some LED's that were being sold off at similar prices thinking I got a bargain. Turns out they have a really high failure rate.
@@uK8cvPAq In my case I think it was the fuse that was of low quality. They're not supposed to explode.
One of my pet hates, people plugging in and out with the switch always on. My family does that, I think they do it deliberately just to upset me.
Yeah me too - but the switches aren't required by the standards, certainly you can buy unswitched sockets and afaik always have been able to. presumably the maintainers of the standards think it's perfectly acceptable to be routinely making/breaking currents of up to 13A on the pins...
@@joinedupjon I don't know if switched sockets appeared the same time as unswitched or if unswitched came first. I only have switched sockets, wouldn't want the unswitched for that reason.
You should turn the appliance off with its built-in switch, then unplug it. Heaters have massive switches. This puny thing is bound to fail; best if they didn't include it at all.
Specified unswitched sockets in my last house. Annoyed the electrician- I think he intended 'acquiring' them... I do not plug/unplug- I switch off the appliance by its switch. Why unswitched? To stop people switching them off at the socket meaning I had to check where, and walk to the socket. A function should only have one control (unless either will work- not require both).
@@joinedupjon Unswitched sockets have their uses, they're particularly useful for appliances under kitchen counters with isolators above & for loads like freezers which you don't want people switching off.
I have found that if the plastering on the wall isn't level, over-tightening the faceplate can crack it. Thermosetting plastic is quite brittle and won't bend around unlevel plastering.
It looks to me that the switch on the faceplate has been used to turn on and off a high current device, rather than using the switch on the device itself. That's going to cause arcing and it will fail eventually. And the arcing at the plug pins shows that the load was switched on when inserting the plug.
The sockets may be cheap, but I think they have been abused somewhat too.
These certainly look like a mechanical thing going on with those cracks.
@John GB ... if that were the case, then screwdrivers would be made as sharp as chisels and as strong as crowbars. Screwdrivers don't come with instructions telling you what not to do, but if you want them to last you don't abuse them.
You wouldnt drive a car to its maximum all day every day and expect it to last a long time.
These sockets were surely certified, if not, the owner shouldn't have installed them. However the sockets are cheap, that's why the owner chose them over a quality brand. They would probably be ok for 'normal' use, but these have been clearly abused. If the owner wanted to give them some heavy duty use then he should have gone for a quality brand.
@John GB ... and there you have it. "If the design is cheap or wrong they won't be given the bs en number". You cant have this both ways. If the design was poor, then they would not have been certified. If the design was good then they wouldnt have failed from just having a 13A appliance plugged in. Yet they did fail. Who knows the state of the appliance! Was it overloading? Did they bypass the fuse with foil? Were they plugging it in on full load and allowing the pins to arc? Yes to that last one!
They may well have made the bs grade, but they were still cheap, that's why the owner bought them, and had little regard for the strain he was subjecting them to. ...a car will pass its MOT but still won't stand up to you thrashing it. The sockets have been thrashed. Don't continually use the insertion of the plug as a switch for your 3kw load, don't continually use the switch on the socket to switch your 3kw load, don't continually do 0-60s in your car. If you do, don't expect these things to last too long. And that's what we see here.
I agree. All you needed was cables badly arranged in a shallow box to end up stressing the front plates and causing them to crack. There is no sign of thermal damage of the front plates causing the cracks. Looks like a poor installation and very rough use, and I am surprised they lasted as long as they did.
With the last assembly, the burn't contacts for the plug pins, looks like the plug has been plugged in and out with the power switch turned ON.
Yes, then again that should not be a problem since the majority of sockets in the world are not switched anyways.
M2 CEF says it all really.
HAGER for me.
M2 Electrical in Redditch, Worcs. These are their 'Soft Edge' range.
So what's your conclusion John? Don't plug 2kW loads in to cheap sockets? All socket outlets are pretty cheap these days including MK and Crabtree. BS 1363-2, it's a bit of a surprise when you look at the standard and realise the current rating isn't 13A x 2 for a double switched socket outlet!
I'm sure M2 is CEF own brand
Chinese made rubbish ., MK have moved firstly to wales from Edmonton then i think to eastern Europe and they are getting poorer in quality and quality control
It is
MK mark various products as 'Made in Malaysia' now. I've had one or two accessories fail in eight years of fitting them almost exclusively. Still considering going elsewhere though; their CU's never have enough earth terminals, there is no sign of them making compact or Type A RCBO's and frankly their website and lack of online engagement make it look like they're stuck in 2001. I now understand they're discontinuing Duraplug, though to what extent is uncertain. I sometimes wonder if they're only bothered about huge companies using their products
i only use Hager, never an issue
@@dg2908 i live in malaysia, they still sell duraplug plug tops
While the socket quality doesn't seem great, i am pretty sure the heater they are using is faulty as hell!!
That last one with burnt socket connections, looks like the fault could be with the plug pins that were pushed into it. The plug may have had corroded and dirty pins. With a large current draw on, say a heater, would cause heat and arcing through dirty pins.
Had the same problem with local sockets. Told by our certifying organisation they were only certified for full power for 15 Min.
They look like pretty okay socket outlets as they go, not great, but not bad. It does look like the issues stem from the possibly filthy pins on whatever was plugged into them looking at the shmoo on the contacts, I dunno,
I wonder if these were just made horribly poorly or perhaps they experienced some vibration which caused constant arcing due to insufficient contact pressure to begin with? Maybe the insides vibrate with the 50 Hz current and cause constant sparks?
This was interesting. The switches seem to be good quality and materials, but still failed due to hard use.
All from one house and one had excessive burning did they have a faulty gadget they were moving around the house destroying the outlets?
My mother has dementia and is in her 90s. She has been doing exactly this. Moving a 50 year old electric fire from room to room desperately trying to burn the house down. All she has done is wreck multiple sockets.
@@mbaker335 Not very nice dementia, when my mother in law got it she burnt an electric kettle by putting it on a gas stove, her brain went back to when she was young. She could remember things that happened 50 years ago but not what happened yesterday.
seen the second one before, had a dodgy cheap USB PSU plugged in, complete with C mark on the back, they did not even manage to fake the E to go with it, those things can get extremely hot and sometimes go boom.
I think the user of these sockets should send you their 2Kw heater......that would likely make an enlightening video.
3X600w lights were misspelled as a 2kw heater -_- lol
They were not exactly the solidest construction, the front sounded rather brittle and probably did not provide much support for the switches. Another possibility is that the electrician did not put the junction box flush with the surface of the wall, or over-tightened the screws, putting strain on the white front. Seem to be a product from the land of Ping-Pong Charlie.
I bought hundreds of cheapo sockets from screwfix many years ago. They failed in the switches pretty quickly. Cost a fortune in fuel and time going back to all the customers houses replacing them over the next 12 months. Never installed crappy sockets or switches since, it's false economy. I used to swear by mk but started to see quality issues with them too over the past 15 years or so.
I thought each of these had a fuse on each circuit. I am only learning about UK wiring from JW's videos.
The fuse is in the plug not the socket. The idea being that the device is fused to what it's rated capacity is, however far too often 13a fuse is supplied as standard with devices. I tend to replace my fuses to the correct one, though I doubt most people bother. It's a nice extra protection to have and can protect the device not just the user.
titerado Fuses protect the cable, not the device.
Those things you called shutters, what are they for? I got an orange extension socket that wouldn’t work. I took it apart again and the red ‘T’ shaped shutter thing seemed to prevent a connection between the 3 pins of the plug and the bits the pins go into, so I took the shutter out and discarded it. The extension socket now works. I don’t see what good the shutter does.
It actually looks like the heat expansion of the ground pins of the plugs caused the sockets to crack. Even if it goes no current in ground normally, the heat of the live and neutral busbars inside the socket, might have transferred heat to the ground pin and/or ground busbars via heat conduction and/or heat radiation, why the ground pin enlarges and splits the socket.
Since these sockets are made out of a "stiff" plastic which are also a bit fragile and brittle (like bakelite, ceramic or glass), any stress inside the ground pin hole, would crack it. Normal socket plastic are atleast a little bit elastic.
The live and neutral pins are jacketed, why the heat expansion of the lead inside the jacket, just leads to a slight melt of the plastic jacket from the inside, and of course the plastic of the jacket itself can compress a bit to give way for the heat expanding lead, and when the plug pins have cooled off again, they can be pulled out without problem. (the contact part of the live and neutral pin of course enlargens, but when they do, they are already inside the socket)
In the UK, all the plastic wall plates are this brittle material, urea formaldehyde, because it is thermoset and won't melt. I guess most sockets just have a bit more clearance around the ground pin
Sebastian - The ground pin NEVER enlarges. Never ever... it just doesn't happen, irrespective of the temperature.
@@johncoops6897 eeh? The ground pin is made of metal. What happens when you heat up metal? Even if its a very little expansion, like on the micrometer scale, if the clearance is too small in the socket (transistion clearance), it would of course split the socket when it heats up. I checked the thermal expansion coefficient for Yellow Brass with Copper Base (C27000), and it has a thermal expansion of 0,0203 mm per *C . It means that if it would heat up 10 degree, from 25 to 35 degree, a 1 meter piece would enlarge 0,2 mm . A ground pin is roughtly a cm on its longest part, so it would be 0,2 mm divided by 100, which is 0,002 mm Its very small, its 2 micrometers. Since we saw discolorations on the busbars, we are talking about temperatures way above that, even above like 150*C-200*C. If we then imagine that this heat might have transferred to the ground pin via radiation and/or heat conduction, lets say that 100*C was transferred, thats 0,02 mm in heat expansion.
@@sebastiannielsen - Sorry, but despite your hypothesising that is simply not the most common way that these kinds of cracks form. Even if the pin did expand by 0.02mm that is still under 1/10 of the allowed height dimensional tolerance (7.8 to 8.05 = 0.25mm) plus there is additional tolerance in the size of the hole too.
Examination of the video at 16:33 shows that the cracks are from top and bottom of the earth hole, so you'd have to base your assumptions on expansion in WIDTH of the earth pin, nominally 4mm.
So if there really was a 100°C rise, we are talking about 8 um (MICROmeters) or 0.008mm expansion of the earth pin. That is simply irrelevant in the scope of this application.
this socket looks premium. i dont think this was made by our friendly china.
I live in Europe, my house is 55 years old, never had any problems with wiring.
The switches on the second socket looked like they had seen more than their fair share of arcing.
Notice the excessive amount of grease on one of these switches. I wonder if the copper is actually copper or brass. The construction of the switches seems to be not very good; not making proper contact due a lack of pressure, perhaps. That would heat up nicely.
@Meghnad (Who roars like thunder behind the clouds)I wasn't clear; I meant to say some inferior alloy (brass or copper colored or coated) instead of real brass or copper. I don't know about the excessive grease: it may become conductive over time? Not sure. At least it looks rather sloppy. I agree that the implementation of the mechanical design seems to be poor, possibly causing bad contacts and, hence, arcing.
As someone said, M2 is a cef company, I installed a USB socket same brand cracked across the front similar to the one you have
@David Parry yes maybe but you would not normally expect a so called reputable retailer do sell this rubbish, and just goes to show that a BS number means nothing, and should stand for bull shit
It’s only some small cracks it’s fine as long as it works
These are RPP M2s, I have a number that have been installed since 2008 and they're all fine.
try 'em with a 2kw heater!
M2 from Cef NICE!
I'm inclined to suspect that it was the same heater used in both sockets and that the plug was overheating. Because I've seen a case where somebody acquired a second-hand heater where the live connection in the plug was loose, leading to overheating and damage to the socket. So he moved it to another socket. And then another socket. And blamed the crap sockets for being defective. The second-hand heater had come from his landlord. Who pointed to the burned socket where it used to be plugged in, blaming the socket for being defective. SMFH.
As for the mysterious arcing on the fluorescent, I have to wonder if there's a kid in the house. A kid in the house who sticks wire across the live and neutral pins of the socket then flicks the switch on and off quickly. Maybe even rides the balance-point of the switch to prolong the arc. Great fun!
This is a poor design, each of the two sockets has four low pressure "brass" metal-to-metal contacts carrying the load current in addition to the actual switch contacts and the contacts with the plug pins. Lots of extra contact resistance and therefore heat dissipation.
John are double sockets actually rated for 2x 13 amp loads plugged into them. I remember seeing a double plug assembly so you could get 16 amp out of a twin socket, I think it came with a welding set. , I would assume that’s a bad idea as the current share could not be guaranteed. Regards Chris
In theory they are Chris, A double outlet counts as an outlet on a ring main.
(And a good question)
And also what the fu..? Double plug assembly?, Jeeze,
Average Joe yes this thing looked like two moulded plugs bolted to a cross bar. I think the idea was meant to be you could only plug them in to a dual socket together thus you couldn’t put just one plug in and have live pins on the other plug. I guess it would have been unsafe on a raised socket. I think they were being sold with welding sets or perhaps a pressure washer. I don’t remember it was 20 years ago. I kind of like the idea if I could get a 16 amp industrial socket to run my plasma cutter at it’s rated 16 amps rather the just turning the ampere down a bit. Kind of arbitrary for me anyway as the garage is run from a 13 amp fused spur. Still working better now i replaced the fuse with a nail. NO I DID NOT replace the fuse with a nail, it was a wood screw. NO I didn’t do that either LOL.
BS1363 has a test for sockets which is 14A in one and 6A in the other, and after a certain number of hours the temperature must not exceed a certain value. So 20A total in theory, if the socket complies with BS1363 - which of course they all should. However there is nothing to stop manufacturers making their sockets better than the standard, so at worst it's 20A, and at best it could be a lot more than that. In any event, a 2kW heater should not cause overheating to the point of cracking things.
MK, Crabtree, Schneider practically never fail, with electricians charging - entirely reasonably £100+ to just walk through the door I have no idea why anyone cheaps out on this stuff, presumably ignorance.
www.m2electrical.co.uk/
Still sold, as far as I can see:- www.m2electrical.co.uk/index.php/wiring-accessories/soft-edge/softedge-sockets/13a-dp-2-gang-double-switched-socket-white.html
They look like a rip off version of silverline
just when you couldnt get any cheaper
additionally, there's a possibility that the plug top has poor connectivity.??
i have experienced before a poor moulded plug top.
never experienced myself any issues with M2, but i do now only use Hager brand, never any issues to date.
It looks like the stuck on socket has a hairline crack on the left socket. It's a shame they didn't send any non-failed sockets to compare them with.
10:40 just joined video lol. . is that a design for a 1 pin socket outlet?? lol
@David Parry
i see they have managed to shrink the technology down somwatt. . . . .get it. . . watt. . . lol
revolting pun i know
@David Parry
cool. . . .lets go to the pub then. . . i can charge my phone there too. . . hopefully not from one of those dodgy socket outlets
@David Parry i am legit amazed as you guessed i am a samsung user. . . i will re-read ypur post again and provide a logical explanation to this
@David Parry
current-cy . . .that was a good one. . and good guess for i am a samsung user. . .our solution is to shake our heads, say ohm dear . . and just go to the pub anyway
and if these failed products keep cropping up , i really will BLOW A FUSE
*13A FUSE HAS LEFT THE CHAT*
I think I know them, I put some in a domestic. Had to go back and replace them.
Looks like a cheap Chinese copy of MK Logic
Recognised genuine name brand equals accountability.
British plugs and sockets are lame....whats with the on/off switches....just another connection point that when weak leads to overheating....and added fire hazard.
Well made British sockets are safe and capable of giving many years of reliable service. The switch isolates the appliance which is far safer than having live leads trailing all over the place. Problems arise when cheap knockoffs get onto the market. Same issue with car parts.
D.P OR S.P 13 amp outlets ? Why the choice, what should be fitted in a standard ring main, and why ?
Video on that is underway, available soon. However the quick summary - doesn't matter, purely personal choice whether double or single pole. Or have sockets with no switch at all.
Are those ground holes large enough? The plates look like they were split by forcing an oversized ground pin into the sockets.
Odd that the contacts on the first one didn't appear to have had any arcing. Also, i'd expect to see some discoloration in the plastic if the thing overheated.
It's a bit odd to see the neutral switched in parallel to the hot. That's not standard practice in the US.
or it could be heat expansion of the ground pin....
Thumbs up for this video J.W. I had my double socket replaced by my council and they were baffled as to why it cracked. The sockets were made by Crabtree and they've replaced it with another Crabtree. My 2Kw heater factory fitted plug was deteriorating ie the fuse cover was starting to melt so I cut that off and replaced it with a BS 1363 13AMP 250V plug top and there's been no heat since. Must be the factory fitted heater plug that was causing the problem.
yes the major issue with heaters is the flex near the plug, it gets stressed and causes a high resistance, cut a few inches off and new plug sorts them
For second socket taken apart the heat mark is where the fuse is in the plug so maybe the fuse was loaded to it's rating and caused the heat mark on the socket?
Absolutely correct.
MK quality is not what it used to be.
These are not MK sockets, nor are they Click Mode. From what other people posted in the
comments they were produced for CEF.
Some MK stuff is still made in the UK, some is made in China. Both might be fine, but they won't be equally good.
Interesting dissection! Is there a chance that a failing appliance that was drawing excessive current but not enough to blow its plug-fuse, spent time connected to the cracked plate units and went full-fault on the 'welded' plate?
Fuses let you draw almost 2x it's rated current for up to 30 mins, but the market is flooded with fakes
John, I recall from one of your previous multimeter reviews lately that you did not recommend using a Cat 1 meter. That being the case. I checked my one, which has never been used incidentally, to find that it is a Cat 2. Can this be used for household mains testing? This is a "Lidl" product and of German manufacture.
There isn't anything wrong with any of the categories, it's more to do with what things are suitable to be used for. Cat I are only intended for use on electronics, low energy devices that are not connected to mains power. Cat II are ok for testing appliances and other items connected to mains voltage circuits. They are not suitable for testing the actual wiring installation, consumer units and similar, which would normally be a Cat III, or Cat IV for the actual electrical supply.
@@jwflame Many thanks, John, for the prompt reply. However, I've since checked the market and find that, for example, the Fluke range is expensive for the amateur so I'll need to purchase a cheaper Cat 111!
At 9:55, it looks like both the live and neutral switch contacts were arcing and appeared like they could be pitting. Once the contact surface was compromised, it was probably starting to overheat, even on light loads. The owner might even have swapped the high current load and usb charger on the different sockets over the years and the USB damage was the final straw. Could be a design fault if they used a cheap alloy that couldn’t survive too many surge current contact closures.
I have the same issue with MK sockets at 2.2 kWh for several months
That's not a lot of energy to use in several months.
@@godfreypoon5148 I said 2.2kWh for several months and not 2.2kW in several months
John, some of the cheapo electronic ballasts (my guess is fish tank lighting in this case) don't have NTC inrush limiting thermistors, so this arcing and welding does happen, more so with substandard switches.
The plug has obviously been inserted with the switch ON in both sides of this socket, the inrush blowing little chunks of metal off both the plug and contact at the point of contact.
Also there won't have been the desired "snap action" when inserting the plug.
Looking at the switches, there appears to be very little contact area between the busbars and the moving switch contacts, that certainly could be a reason for the switch overheating.
Fine China
Buy MK ....;)
Mmmm. Give me MK or Crabtree every time!
I'd say the problem isn't with what you have but what was plugged into them.
Has the brand of those outlets been identified yet?
M2, available from CEF.
@@jwflame So, based in the UK but I guess made in China like most other things. Does M2 gear have a good or bad reputation among electricians?
@@James_Bowie I fed up with British companies purchasing cheaply made products from China to make a profit.
Not to the British Standard of safety. 😳
So what’s the science behind overheated loose connection? Is it the arcing that creates the heat or the fact that the high resistance connection acts like another resistive load thus drawing more current? I’m a bit confused here. Thanks
Probably both... the first (bad contacts) creating arcing & heating, and that caused the second issue (soot, pitting and increased resistance) which compounded matters... things spiral downward quickly from there.
If you have high contact resistance then that is in series with the load, so the total current draw is actually slightly less.
The problem is the contact resistance dissipates significant power when current flows through it and gets hot. Power is current squared times resistance. For a 2kW heater the current is about 8A. So even a resistance of 16 milliohms will dissipate 1W and that will generate significant heat in a small contact.
@@nophead: you're right, your description of the heating is better.
Thank you both. It’s much clearer now. Looks to me that a bad contact creates an area of very thin metal and acts as a sort of filament in in bulb.
It appears the switches are the weak point in these sockets, I wonder if it's a common issue of the design or more specific to some manufacturers/models of sockets
this is a cheap knock off, the design itself is fine, but a bad copy with poor materials, such as if the switch end melts under heat it puts less pressure on the switch and causes more heat and fails, if they used an inferior copy of the materials
If it was, it would be very common as the vast majority of British sockets have switches.
Do us UA-camrs ever sleep? LOL almost 2AM and we're uploading!
You would be shocked at the amount of am small hours we on the conspiracy exposure side of things have to put in due to the censorship levels we have to endure, all thanks to the monopoly control of the Terrorvision and all MSM.
Or maybe he just set the upload to start and the system published it for him after the upload finished? I'm not sure how it works since I'm not a producer though.
This video was uploaded 6 days ago.
+ John Ward - Just want to thank you for your great videos and for helping us. I have watched all your videos and have learned a lot from you. Cheers.
That why it's not good to have 32A in front of a socket that can only handle 13A.
Unless the appliances were at fault, the sockets were only supplying 8 amps. If the load of the appliance had exceeded 13 amps, the plug fuse should have blown.
@@alanpatterson2384 If you had 13A fuse in the fuseboard, the cable and socket could not be overloaded. Its very easy to overload the socket the way your installing it, just put two 13A loads in to a socket like this and you will excide it with 100%
@@mortenwinslw2785 If you did that you'd only have 13A available on the entire spur, which could be several sockets.
There are two lots of wire between the breaker and the socket, and the fuse in the plug will stop the current when it blows. BS1363 specifies fault conditions the socket outlet must survive.
Morten Winsløw so how do you suggest we wire the fifty plus outlets in my house? Fifty individual circuits? Stupid. We have some of the safest electrical standards in the world.
Typical cracking from a square hole. That's why aircraft tend to have round windows.
Does the door to your room have a similar crack? I assume it has 90 deg corners too?
@@MrSwanley yes but the expansion and contraction are easily absorbed by the large frame but I did have cracking there when the house was new now filled .
@@barrymayson2492 - My butt has a rounded shape, yet there is a huge crack in the middle!
Barry Mayson cracks in sockets are usually caused by overtightening of the screws, or someone tripping over and yanking the cable out.
Polycarbonate is an odd material, as it is really flexible yet will develop cracks if it is stressed for long periods. A crack like those in the power outlet could actually be caused by the plug having incorrect pin spacing or being bent. *EDIT* Please ignore that... I was unaware that Britain still uses a "bakelite" type brittle plastic for these covers. The rest of the world made that material non-compliant a LONG time ago, because itso easily cracks and reduces electrical safety.
john ward would you please stop mumbling when you speek and form your words correctly.
Have you ever watched your own videos please do so you will then understand what i mean.
This is not meant as a insult please don't take it as one it is constructive advice.
good videos
Gee, the mandatory 13A HRC fuse in the plug didn't do a bloody thing to prevent the over-current failures on the second socket.
BTW - those faults don't look like they could possibly be caused by a 2x54W T5 fluorescent. Looks like a large inrush current load without a separate switch has been controlled on and off via the socket switches.... when they failed, then the user just plugged the load in, causing arcing of the plug pin contacts.
Too ashamed to put their name on the junk by the sound of it
16:20 - re: the cracks of faceplates, it is very odd that this is attributed to overheating. I'm in Australia and brittle materials like UF are no longer used here. I've quickly reviewed BS1363-1 and -2 and I cannot see any requirement to use "thermoset" plastics, let alone brittle UF etc. The standard requires that materials must pass tumble barrel and other mechanical testing, plus material is NOT required to be "fireproof" but simply to be self-extinguishing (
When it comes to my HiFi separates I polish all the plug pins each year with brasso and zero grade wire wool, dirty pins and poor contacts cause issues when you try to pull a decent amount of current.
Bizzare failures.
Why not.. before any dismantling, shove many amps (13) through the socket and do an overall socket resistance and power loss calculation. You could leave it on and see if it gets worse..thermal runaway..?
These things should have a contact resistance spec, but I've never seen one
Wow your T s and Ss are loooouuuudddd😆😆😆,once you notice it ,it's bloody irritating😆😆
So why watch?
@@westwonic I didn't😃when it started to break my brain ,I turned off and expressed my concerns. Have you been practicing,your S's ,R's & T's? I learnt mine years ago, good luck