As someone who's not in the industry (but has done some basic training at college 10 years ago), I loved this video. Very satisfying to see a smart factory set up, but also great to see companies still taking pride in their work. Amazing.
I can remember when cable went metric .electricians at the time hated the fact twin and earth cable changed from stranded to solid cores. They soon got used to it though. But single conduit cable well into the 80s was available in sold or stranded core. Great video thanks
Different standards in different countries, in Australia all domestic use cables over 1.0 sq mm are stranded, we also have an insulted earth conductor and our standard sheathed single phase twin and earth stayed as red and black cores, which personally I think was silly. Very interesting video, it's also good to see not all manufacturing has gone to Asia.
That was very interesting. I never realised how the cables were manufactured, so thank you (and Doncaster Cables) for your video. I do not regret the passing of 7/.029 like one of the comments, but I have always thought the previous colours of red, black and green were better. Then, 3-phase supplies were coloured red/yellow/blue. Simple and neutral remained black as in T & E. Even worse is the "50 shades of grey" in SWA.
As an American EE/DIY spark, can confirm that the old colors you used are way better than the new and are on par with our color code for ease of wire differentiation.
Enjoyed that! great video thanks 😎 love this stuff. I also like the fact you get an extra 1m of cable lol. All those saying "why don't they put a sleeve over the cpc? " it's because they have to make it to a British standard, regulations, thicker outer sheathing, conduit capacity, glanding, clips, etc.. and certification would all have a massive knock on effect of the price, and installation. would be nice though lol.
this is so cool! I sold tons of this stuff back in the 1980's and 90's... here in North America we call the cable "Romex". This is such a neat video! Thank You Guys!
The cable manufacturers in Sweden has stopped using chalk to save our hands from drying up and not having to clean up the mess i makes. The newer types of cables are really easy to strip, often no problem to strip >1 meter of outer sheeting with minimum force
Super interesting, espescially, as a north american, to see how you have cables with chalk in them, here we have paper separating the different conductors!
I used to work for CEF Doncaster cables was sadly one of the factories I didn't get to have a tour of. I did however handle a hell of a lot of cable from this factory during my time there. I still have half a roll of 1.5 and 2.5 in the shed.
One of the biggest secrets was how the manufacturers took the opportunity when metrication was introduced by moving from stranded to solid cores,they tried it with singles too but conduit wiring became almost impossible so they had to return to stranded,I’ll keep my 7/029 ring main cables thanks
Fascinating video but when I went to click on the video link at the end, it cut straight to an ad. Maybe leave the links on screen for a little longer next time.
Interesting to see the process. I once had a reel of 1mm t+e cable where, on part of the reel, the neutal and cpc had managed to "switch places" within the sheath during manufacturing. The conductor order was now Line - Neutral - CPC. I didn't realise until I came to do my pre-test (end of 1st fix) and while it was a bastard to strip - it still passed cont and IR with flying colours so I decided to leave it in place (given that it would have been an extra 2 days labour to replace it). Anyone else ever had this issue? Never seen it before or since but now i''m super vigilant about it.
We used to get some crap cable from my wholesalers about 25 years ago .. Not through choice. It was called Wessel . Half way through the drum it would turn thin and even almost round. Full of kinks It wasn’t just a one off. It was still BASIC approved and tested ok.
We don't have that in US residential cable. Maybe a collaboration with electrician u channel on the differences of UK and US power systems and standards.
There must be a load on the other end. Probably a high voltage and current test all in one. I wouldn't have thought there could be this much leakage current. with all that insulation.
@@rbland There isn't a load on the other end, there would be no point in doing that. With a wire diameter of 1.4mm, a separating distance of 2.5mm and a pvc dielectric constant of 3 I've calculated a capacitance of 70pF/m, so at 10km of wire and 50hz there's an impedance of ~4550Ω, giving a current flow at ~3kv of 0.65 amperes. Purely capacitive.
Any technical reasons or otherwise, are the drums of the cooper need to be of 8mm in diameter ? Just curious Couldn’t the cooper wire manufacturer produce them in different diameters needed for different purposes and sell them to electric cables producers the exact diameter that they need ? Side question - is similar manufacturing process of drawing out the raw copper cables into different diameters apply to making cables for the audio visual industry too ?
It will be because it's the standard but also because it means that the cable manufacturer has greater control over the drawing and annealing. Relying on a supplier to manufacture to the standard you want can complicate things, for example if demand shifts or equipment goes down you wouldn't be able to shift production until the new wire works its way through shipping.
What always surprises me is that the UK twin and earth allows smaller conductor for PE/CPC. This would never be allowed in the Scandinavian/Nordic countries, where the earth has to be the same area, or equivalent conductivity. Although we allow plastic consumer units, open ends on surface mounted plastic conduit without requirement to bend it with the cable showing out in the corners…
The earth wire should never carry current except in the case of a short duration pulse (until the MCB trips) of a line to earth fault. Therefore it only needs to be big enough for this requirement.
@@apk55 Good point… but what if the fault current wouldn’t be enough to trip the circuit breaker, let’s say if the cable were to be quite long? Nowadays when an RCD is installed I guess it wouldn’t be an issue, but what if the RCD was faulty? I know this is very unlikely to be a problem but I think it’s just interesting to see how we do it differently.
@@apk55 The earth here in Germany has to be large and low resistance enough to clamp the fault current to a safe enough voltage in absolutely all situations. Which is hard to do if you get a line-to-earth short at the end of any disstance of cable run with the earth being a thinner conductor.
Similar process in Canada .We call it Romex .We do not make Romex with an isolated ground but do make BX Armoured cable with isolated ground .Used for Data Communications and hospital environments..Most cash register systems in groceries stores will use isolated grounds as each till and computer will have an independent UPS
@@efixx pretty much the same thing we use 14 or 12 gauge for most residential applications .We also have a heavier jacketed version with the NMW-U rating .Non metallic wreathed proof and underground rated .It can be run on the surface above 1 meter without mechanical protection or underground .the insulation is almost 3 times the diameter of the conductor and the ground wire is the same ,bare . Armoured cable comes in various configurations .Lead core aluminium spiral and PVC inner or outer jacketed cables .Tech cable is a brand name can be a single conductor or multi conductor .Shielded or unshielded .The sky is the limit and so is the price .Some we use are over $8 Canadian a linear l foot /Or everything now is metricated .Dont know metric ,not conduit nor wire sizes .AWG ,Kcmil and MCM .,1/2,3/4 ,1, 11/4, 2 inch 3 inch and 4 inch conduits .Never used metric except in school and European equipment .Construction for us as always been imperial inches and thousands of an inch for machinery .
Interesting watching the manufacturing process. Cable looks similar to UF (underground feeder) cable on this side of the pond. Typical indoor flexible cable in the US NMC (Romex) has paper between the conductors and outer jacket. I was surprised by the wire twisting process on larger gauge, I was expecting to see the take-up spool being rotated.
Different colors used here in the US, but The end product looks to be physically the same. US wire is normally certified for 600 VAC for this type of cable. Anyone know what it is in GB?
Fascinating - you'd certainly need your wits about you to walk around that factory, not a good place for loose clothing or trailing jewellery, etc!! Thanks for sharing.
@@Bari_Khan_CEng_CMarEng Yeah, exactly that - if that chalk isn't there the different layers just get stuck to each other and especially if its on an existing older circuit that's had some use (And therefore heat) it can be literally impossible to remove the out sheathing! On a new install it's generally just irritating and a waste of time - you have to do it at each and every point!
And when we went metric the manufacturers seized the opportunity to go from stranded to single core which benefitted them but caused problems for electricians,particularly in conduit wiring so single soon returned to stranded.Unfortunately T&E was left with solid conductors making it stiffer and less easy to ensure the tightness of tunnel terminals.7/029 was superior to 2.5 in every respect
Hey thanks for sharing I live in the caribean and never saw dual earths before. Could you explain the reason. Also another question would be why have we moved from red and black to blue and brown
I'm not an electrician but I've never seen this type of cable, is it a British thing? AFAICT here in France the earth lead is always identical to phase and neutral except for the color of course (yellow and green)
Wow what a brilliant video. I found this very interesting, One question though if the cable is tested to 3KV for five minutes why is it when we get it it’s only rated to 250V? . Gaz this is one of you’re best videos more like this please. Brilliant video Gaz as always 👍👍👍👍👍👍👍👍❤️❤️
@@FistralG he said “the high-voltage test procedure will test each core to every other metallic component within the cable”. Also he mentioned the voltage was applied for a period of time. Therefore this appears to be a “dielectric withstand” test. The idea is that no current is flowing.
@@MatSmithLondon There was a small current displayed on the screen. My point still stands it’s not tested with a high voltage and high current. That’s why it’s only rated to 250v in real life use.
@@FistralG I still can’t get it. I understand current carrying capacity of cables, what I don’t get is irrespective of the current, if the cable is tested to 3KV then surly it would be rated to 3KV why is it only rated to 250v , even if it was rated to 3KV if to much current flows through it it will overheat and melt . Also if it’s rated to 3KV then it will have a much higher current carrying capacity making it ideal for domestic installations as we wouldn’t have to worry about over loading and fires ?
@@Dog-whisperer7494 It's an insulation resistance test. HV is used at very low currents, as you would do with a IR tester on testing a final insulation, but only to 500V or 1000V on a multi tester, If it passes a test in the factory of 3KV then it will certainly pass an IR test after installation and test. It's "headroom" for its capability of IR.
If the cable is IR tested at 3kv how many times can it withstand an IR test above 1kv after that ? Only asking as I have carried out IR testing at 5kv and could only perform that test once. After that any more HV testing would destroy the cable.
I know I'm just an American. But what is the powder in the wire? Our electricians here would never go for that. I know they are allergic to brooms and vacuums so that would definitely not help things for them.
I always thought the color of the cables is reversed. So easy to remember if blue was the hot or the sky, and brown was the return or ground, like in dirt. Anyone know how these colors were originally determined?
we still use red & black in australia, only appliance cord and leads have blue & brown sleeves. i think the colour change was for colour blind people because when i did my apprenticeship you couldn't be a sparky if you were colour blind. and apparently only men get this ,most sparkies were men back then so testing was necessary because multicore cables can have lots of colours in them that can be mixed up by being colour blind.
Red and black can cause issues with people that are colourblind. Apparently blue and brown can be distinguished. Always remember you would not touch a turd and they are brown.
Thank God it is not made in China, as we would end up with crap wiring in our homes and not the real thing! Nice to see we still make something in the UK
coming from nz, the non insulated earth has always annoyed the bajesus out of me. ive gotten used to it being solid instead of stranded, and in some ways i actually think thats better,
Now you need to do a video on the biggest electrical question, to twist or not to twist? So many sparks, even on RU-vid, don't seem to twist cores anymore, they just shove the ends in and hope the screw catches both as if they're a plumber. When I was an apprentice behaviour like that would have got your toolbox screwed to the floor. 🤣
I'm gonna make a video titled "How A Chevrolet Tahoe is Made" and its going to go like this... "So we're going to start with a Chevy Suburban and make it smaller, then paint it"
Interesting vid, but I find it ridiculous that most cables are still PVC. It is one of the most toxic plastics to manufacture, is not easily recyclable, and indeed in many countries they simply burn big piles of cable to remove the PVC and get the copper for recycling, producing some seriously toxic pollutants like dioxins and furans in the process. Given that there are better alternatives, like synthetic rubbers which are less toxic, tougher and more heat resistant, it's hard to see why PVC is still the dominant sheathing material other than it's cheaper. But, I guess it all comes down to price in a capitalist society, things that actually matter like environmental issues always come last...