45 years as an industrial electrician and actually surprised how long the smaller cables held up. Seen a lot of burnt out cables in industry but usually due to bad connections. Of course had they actually been carrying mains electricity things would have gone bang a lot sooner as the cables would short together. Would be interesting to set up a cable with the different installation methods.. chipped direct, buried and insulated etc 👍👍
Yes it is, glad I'm not the only one who finds it interesting, please share with like minded or maybe even like and subscribe. Check out my other videos.
I guess this is an ideal situation with no enclosure at all, the point you worry is when the plastic softens not burns as you can probably get shorts if it does. Plus there is also voltage drop to worry about, and that must have been significant at these currents.
I also find it quite terrifying as someone could be overloading a line for quite some time thinking it's perfectly safe when actually it's actually right on it's tipping point, waiting for someone to plug in a hair dryer before it burns the building down! Schools need to teach *_everyone_* this stuff, not just people who want to work with electicity.
My grandma whole kitchen is wired with 2.5mm2 😂 including oven, dishwasher and 4 hob induction cooker. It never tripped. I was amazed when I saw that and asked how was it possible the breaker never tripped, she said she never uses two appliances at the same time because she's basically a cheapskate 😂😂😂
You really should have let the cables sit at their maximum rated current (whilst clipped to a surface) and wait for the temperature to stabilise to give a proper indication of how appropriate the temperature/current ratings actually are. Then once stabilised creep the current up slow enough that the cable temperature tracks or turn it up a step and then wait for the temperature to stabilise again and see how the insulation copes with that. In Aussie land our most common insulation spec for flat wires such as these is V90, ie PVC 90c, but in normal installation it's only rated to 75c with 90c requiring it to be installed in such a way that it's not under mechanical stress to avoid push through.
Thanks for watching, please share with like minded people, we have cables rated at 90°C. but this also means connections must also be rated at the same temp or higher. I simply just wanted to show excess current passing through cable, but if I do it again I may leave it longer. Can I ask what the initial ambient temperature is us Australia? Again thanks for watching, may like and subscribe.
Great "illustration"! We chose 6mm² over 4mm² for a planned 3ph PV at a scanty 13kW max for 12 meters. My wife feels safe now, but from an engineering side both diameters are clearly over-spec'd.
Glad it was reassuring! Always better to be on the right side for cable design especially as certain loads are sustained at maximum for long periods. Please share with like minded people or maybe even liek and subscribe.
Is that what he is doing, surely he has got more pressing things to be getting on with, thanks for watching, please share with like minded people or maybe even like and subscribe.
Nice test. A test for real world scenarios would be nice. For example a final ring is limited to 32A by its breaker. It has a ring of 2.5mm cable. If the ring is broken the 2.5mm may have current run through it, over its rated maximum. Best case scenario is 27 amps, most is less because of derrating. So if a 2.5mm cable is rated at say 24A and has 32A run thought it, 8 amps higher than the max, how long would it last and what are the adverse effects? Also, a breaker takes far more than 32A before it breaks.
Great suggestion! Please share with like minded people, I will maybe put one together and see how long it will indeed last, thanks again, please like and subscribe.
@@sparkyhelp3997 Our Continental neighbours say that final rings are dangerous as if they break the cable is liable to catch fire as the MCB will be too big for the cable. As if 32A in a 24A rated cable will instantly burst into flames. Well the recommended AFDDs should catch some breaks.
A few years back i went to a job where the client had no upstairs lighting working. I found the upstairs lights on a 40A Wylex plug in type mcb and on further inspection found that her ex partner had installed a 8.5kw electric shower off the lighting circuit ! The cable had obviously failed (client informed me the shower had been in for a few months) Amazing really that a cable can take such loads. Off subject, i had to disconnect and remove the double socket that the ex partner had fitted over the bath! perhaps he was after some life insurance money!!!
It takes all sorts, the problem is the person who installed it would have just said "it works though!" Please share with like minded people or maybe even like and subscribe.
Hi Please Create a Video on Like different types of cables as such and where can we use which of them like 1.5 mm 2.5 and so on and how many appliances we can put on on each of the cable thanks.
Thanks for watching please share with like minded people. I will do other videos, but please check out this in the mean time - ua-cam.com/video/p4Bxog90TXA/v-deo.html Please like, share and subscribe.
Curiosity question (and I isn't a sparky) what is the ambient temperature of the room you are conducting this test in or outside air temp if done outdoors? We have hot summers her in Oz so the air temp is often 30°C or hotter so would that lower the amount of amps the cable could carry before the cable self-immolates especially the lower gauge cables like 1.5mm? Ta. 👍 In the early 1980s I made cables like this for Associated British Cables and the plastic had a melting temperature of about 160°C to 170°C. Never saw one tested to destruction but I know if I saw a cable actually melting I knew what the temp would be like. Fun fact. When a cable was tested a pinhole in the plastic sheath could be detected *and* found on a drum of a couple of thousand metres. When the pinhole was found the repair guy would get a single granule of the plastic which was about 3mm in diameter and would manually melt the granule so it would cover the pinhole. Cable was then sent to the winding department and wound onto the smaller spools that you guys buy at the supply stores. Interesting job.
Hi, thanks for watching, this was carried out outdoors, the temperature was about 18° C on this day. You are quite correct the values of current carrying capacity have been tested in an environment of 30°C If the ambient temp was higher the current carrying capacity would be lower and vice versa if you could guarantee lower temps then the current capacity would be higher. Thanks for your question please share the video or maybe even like and subscribe. Again thanks.
I think ambient is less of a concern, as to what environment the cable is installed. ie insulated ? covered ? anything flammable nearby etc etc. The small range of ambients most of us live in, not so much of an issue. but either way, for these tests, thermal imaging is essential to see when the actual cable is at a high risk temperature
I’ve just started my L2 electrician course and I am getting deep into the weeds on these types of videos. Yours are excellent. Very informative. It is quite interesting to see how much amperage these cables can actually handle.
@@sparkyhelp3997 Good content, thank you. I know it takes so much time to put a video together. If I may add a little suggestion of my own - watch some E-Fixx videos and have a think about how you speak in your videos compared to them. You'll notice that the skinny guy is very calm, like a warm chat with a friend. The other bloke usually uses a more artificial 'presentation' voice - more intense, often in the higher pitch. I respectfully encourage you to try to be more like skinny-guy - more calm, more natural. You're doing what you enjoy, for your audience to enjoy. Speak to us like you would a friend in the room with you. All the best.
Hi Thanks for watching please share with like minded people. In most cases it is the insulation that is the limiting factor on current rating as copper melts a1084°C. Please like and subscribe.
intresting video ,but i must tell you just how poisonous the burnt cable sheath is , it actually travels thru the skin ,ask any fireman why you dont handle burnt cables with bare hands ,please bear this in mind going forward
Hi Thanks for watching, please share with like minded people, I did research this topic, but only found information of the flame propagation and gasses given off. I will bear it in mind, as after all the construction industry used asbestos for a long time without knowledge of its detrimental risks to health . Again many thanks gloves would be advisable in future better to be safe than sorry. Please like and subscribe.
45 years as an industrial electrician and actually surprised how long the smaller cables held up. Seen a lot of burnt out cables in industry but usually due to bad connections. Of course had they actually been carrying mains electricity things would have gone bang a lot sooner as the cables would short together. Would be interesting to set up a cable with the different installation methods.. chipped direct, buried and insulated etc 👍👍
Hi Thanks for watching, please share with like minded people, I may have to try different installation methods, Please like and subscribe.
Its amazing just how much current these cables can withstand against how much they are rated for in BS7671, very interesting experiment!
Yes it is, glad I'm not the only one who finds it interesting, please share with like minded or maybe even like and subscribe. Check out my other videos.
I guess this is an ideal situation with no enclosure at all, the point you worry is when the plastic softens not burns as you can probably get shorts if it does. Plus there is also voltage drop to worry about, and that must have been significant at these currents.
I also find it quite terrifying as someone could be overloading a line for quite some time thinking it's perfectly safe when actually it's actually right on it's tipping point, waiting for someone to plug in a hair dryer before it burns the building down!
Schools need to teach *_everyone_* this stuff, not just people who want to work with electicity.
@@daveansell1970 This is exactly what's happening, in a real install cables are covered quite often by insulation and other building fabric.
My grandma whole kitchen is wired with 2.5mm2 😂 including oven, dishwasher and 4 hob induction cooker. It never tripped. I was amazed when I saw that and asked how was it possible the breaker never tripped, she said she never uses two appliances at the same time because she's basically a cheapskate 😂😂😂
Perfect videos, and brilliant to share with my college apprentices and other tutors. Been looking for something like this for a while. 🎉
Glad it was helpful! Please share with like minded or maybe even like and subscribe. Again many thanks.
You really should have let the cables sit at their maximum rated current (whilst clipped to a surface) and wait for the temperature to stabilise to give a proper indication of how appropriate the temperature/current ratings actually are. Then once stabilised creep the current up slow enough that the cable temperature tracks or turn it up a step and then wait for the temperature to stabilise again and see how the insulation copes with that. In Aussie land our most common insulation spec for flat wires such as these is V90, ie PVC 90c, but in normal installation it's only rated to 75c with 90c requiring it to be installed in such a way that it's not under mechanical stress to avoid push through.
Thanks for watching, please share with like minded people, we have cables rated at 90°C. but this also means connections must also be rated at the same temp or higher. I simply just wanted to show excess current passing through cable, but if I do it again I may leave it longer. Can I ask what the initial ambient temperature is us Australia? Again thanks for watching, may like and subscribe.
@@sparkyhelp3997 Normally v90 is only used to 75c but it does open possibilities. The ambient temperature assumption is 40c.
Great "illustration"! We chose 6mm² over 4mm² for a planned 3ph PV at a scanty 13kW max for 12 meters. My wife feels safe now, but from an engineering side both diameters are clearly over-spec'd.
Glad it was reassuring! Always better to be on the right side for cable design especially as certain loads are sustained at maximum for long periods. Please share with like minded people or maybe even liek and subscribe.
Good future with Keir getting his friends to be sparkies!
Is that what he is doing, surely he has got more pressing things to be getting on with, thanks for watching, please share with like minded people or maybe even like and subscribe.
@@sparkyhelp3997 His "new" friends all get 7 virgins so the incentive to get them early is real!
Nice test. A test for real world scenarios would be nice. For example a final ring is limited to 32A by its breaker. It has a ring of 2.5mm cable. If the ring is broken the 2.5mm may have current run through it, over its rated maximum. Best case scenario is 27 amps, most is less because of derrating. So if a 2.5mm cable is rated at say 24A and has 32A run thought it, 8 amps higher than the max, how long would it last and what are the adverse effects?
Also, a breaker takes far more than 32A before it breaks.
Great suggestion! Please share with like minded people, I will maybe put one together and see how long it will indeed last, thanks again, please like and subscribe.
Keep in mind the breaker also activates on temperature. The heat of the copper would transfer to the breaker and eventually trip it
@@sparkyhelp3997
Our Continental neighbours say that final rings are dangerous as if they break the cable is liable to catch fire as the MCB will be too big for the cable. As if 32A in a 24A rated cable will instantly burst into flames. Well the recommended AFDDs should catch some breaks.
Great video. Always wondered how much it would take to melt the cable above its rating
Glad it helped, please share with like minded people or maybe even like and subscribe. Check out my other videos.
Any chance of showing how insulation over cables derates them, ie the heat.
Hi thanks for watching, please share with like minded people, maybe I will take a look at doing this. Please like and subscribe.
A few years back i went to a job where the client had no upstairs lighting working.
I found the upstairs lights on a 40A Wylex plug in type mcb and on further inspection found that her ex partner had installed a 8.5kw electric shower off the lighting circuit !
The cable had obviously failed (client informed me the shower had been in for a few months)
Amazing really that a cable can take such loads.
Off subject, i had to disconnect and remove the double socket that the ex partner had fitted over the bath! perhaps he was after some life insurance money!!!
It takes all sorts, the problem is the person who installed it would have just said "it works though!" Please share with like minded people or maybe even like and subscribe.
Hi Please Create a Video on Like different types of cables as such and where can we use which of them like 1.5 mm 2.5 and so on and how many appliances we can put on on each of the cable thanks.
Thanks for watching please share with like minded people. I will do other videos, but please check out this in the mean time - ua-cam.com/video/p4Bxog90TXA/v-deo.html
Please like, share and subscribe.
Very informative
Hi thanks for watching, please share with like minded people or maybe like and share.
Curiosity question (and I isn't a sparky) what is the ambient temperature of the room you are conducting this test in or outside air temp if done outdoors? We have hot summers her in Oz so the air temp is often 30°C or hotter so would that lower the amount of amps the cable could carry before the cable self-immolates especially the lower gauge cables like 1.5mm? Ta. 👍
In the early 1980s I made cables like this for Associated British Cables and the plastic had a melting temperature of about 160°C to 170°C. Never saw one tested to destruction but I know if I saw a cable actually melting I knew what the temp would be like.
Fun fact. When a cable was tested a pinhole in the plastic sheath could be detected *and* found on a drum of a couple of thousand metres. When the pinhole was found the repair guy would get a single granule of the plastic which was about 3mm in diameter and would manually melt the granule so it would cover the pinhole. Cable was then sent to the winding department and wound onto the smaller spools that you guys buy at the supply stores. Interesting job.
Hi, thanks for watching, this was carried out outdoors, the temperature was about 18° C on this day. You are quite correct the values of current carrying capacity have been tested in an environment of 30°C If the ambient temp was higher the current carrying capacity would be lower and vice versa if you could guarantee lower temps then the current capacity would be higher. Thanks for your question please share the video or maybe even like and subscribe. Again thanks.
I think ambient is less of a concern, as to what environment the cable is installed. ie insulated ? covered ? anything flammable nearby etc etc. The small range of ambients most of us live in, not so much of an issue.
but either way, for these tests, thermal imaging is essential to see when the actual cable is at a high risk temperature
no time limit current is 5A/mm*2, for short period of time is 10A/mm*2, everything above 10 A/mm*2 can cause insulation melting
Many thanks for watching, please share with like minded people maybe even like and subscribe.
Just leave the camera alone next time!
Many thanks, I need two camera to take multiple angles. Please share with like minded or maybe even like and subscribe.
I’ve just started my L2 electrician course and I am getting deep into the weeds on these types of videos. Yours are excellent. Very informative. It is quite interesting to see how much amperage these cables can actually handle.
Best of luck! Please share with like minded people, or maybe even like and usbscribe.
Nice video.
As you can see, ‘as you can see’ is completely not needed in the dialog. :)
Great comment, thanks for watching though, you could always mute it. But thanks for watching - I will sack the script writer.
@@sparkyhelp3997 not sure how muting it would help. 😂
@@sparkyhelp3997 Good content, thank you. I know it takes so much time to put a video together. If I may add a little suggestion of my own - watch some E-Fixx videos and have a think about how you speak in your videos compared to them. You'll notice that the skinny guy is very calm, like a warm chat with a friend. The other bloke usually uses a more artificial 'presentation' voice - more intense, often in the higher pitch. I respectfully encourage you to try to be more like skinny-guy - more calm, more natural. You're doing what you enjoy, for your audience to enjoy. Speak to us like you would a friend in the room with you. All the best.
Note thou to destroy the cable the current needs to be much higher than the ratings.
Hi Thanks for watching please share with like minded people. In most cases it is the insulation that is the limiting factor on current rating as copper melts a1084°C. Please like and subscribe.
intresting video ,but i must tell you just how poisonous the burnt cable sheath is , it actually travels thru the skin ,ask any fireman why you dont handle burnt cables with bare hands ,please bear this in mind going forward
Hi Thanks for watching, please share with like minded people, I did research this topic, but only found information of the flame propagation and gasses given off. I will bear it in mind, as after all the construction industry used asbestos for a long time without knowledge of its detrimental risks to health . Again many thanks gloves would be advisable in future better to be safe than sorry. Please like and subscribe.
Mainly aimed at some types of rubber as it can form a dangerous acid residue called hydrofluoric acid
So what I take away from this is 2.5 is good for at least 40A. Won't be buying anymore 6mm in future. Cheers 👍
Hi thanks for watching Please share with like minded people, maybe have a fire extinguisher on standby... Please like and subscribe.
In free air... try packing a few cables together or run them in spaces wheres no ventilation going on. 40A will surely make it fail after a few hours
K
Many thanks please share with like minded or maybe even like and subscribe.