Inside a supplier's cut-out

[@MartiA1973]

Nine minutes of solid information; Thank you David.

[@neil03051957]

the 100amp rating on the fuse carrier refers to the max fuse rating that the carrier is designed to carry. cheers good video.

[@mc_cpu]

Nice to see inside, less chance of people opening them up out of curiosity.

[@michaelcostello6991]

Really interesting to see this opened up. Also i appreciate the extra emphasis you put on the dangers as you really have no protection from electrocution or ARC flash.

[@markandrews8437]

I'm an adult trainee (52) just an am2 to do then the real world,thanks for the videos they've been very interesting and informative keep them coming and thanks for sharing

[@dsesuk]

Thanks Mark, Good luck with the AM2!

[@sdgelectronics]

TNS supplies will often still terminate in the service head, it will just no have the internal link fitted. It's only where the supply cable is PILC that you will see the external connection to the cable sheath.

[@Satters]

ahh yes, split concentric cable, that's caught a few people out in the past thinking a supply was TNC-S, when in reality it is TNS, have also experienced faults service joints failing on split concentric, giving a disconnected neutral, with all sorts of nasty consequences.

[@TheDrdoom666]

Another great piece of information. Thank You...this sort of stuff should be taught in the later years of school along with taxes, mortgages, savings, investments and basic emergency aid...even put this on TV in place of all the crap that is on. OK that is my rant over with...sorry.. As I said Great video and truly life saving information.

[@rayg9069]

I like that network cutout box, we have nothing like that in Australia, it's usually either an overhead supply straight into a sealed exterior mounted service fuse or underground supply into a consumer board mounted sealed service fuse then the meter. I have never heard of anyone, electrician or not having trouble with the network suppliers for pulling a fuse if there is a safety issue. Much better a bit of paperwork than a dead person.

[@horatiofluffytop]

Really excellent video David, thank you.

[@bikerchrisukk]

Really fascinating, well done for taking the time to make the video.

[@mrbeckles77]

Great video David! Very informative. Are able to give a link to the authorised company you use to pull the fuse? Thanks

[@dsesuk]

Hi Jason. I use Haste Ltd. www.hasteltd.co.uk - it was my NICEIC assessor who gave me their name, so I called them up and opened an account. That allows me to book their engineers when I need a fuse pull or isolator installed. If I remember rightly, it's about thirty quid for a fuse pull, sixty for a single phase isolator, plus VAT. I add on a modest management fee when charging my end clients to cover the time in arranging the booking and handling the invoicing. It's a lot cheaper than the likes of Western Power would charge - I had one client once who reckoned they'ed forked out £150 for an isolator install!

[@chrisjason3486]

That's Right!.... That's the DNO Side. I know a few Electricians who have removed 100 Amp cut out seals /Removed without written permission. Most supplys I work on recently have a Double pole isolator between the meter conductor's 👍

[@ianhill20101]

Prepare the method/risk paperwork, grab the raybans marigolds and rubber stilletos from the van. Dead short the tails pop the main fuse boom safe isolation with no tags broke or fines occurred all while passing the competent recognition for napit.

[@metallitech]

Guys, our house has a three phase service head which probably dates back to the 1950s. If the grid changes it for a new one, should they be willing to replace it with another three phase one? Do you think it will cost us extra?

[@dsesuk]

It's the district network operator's duty to ensure you have a service head that is fit for purpose. If the existing one is old and requires replacement then they should undertake it at no cost to yourself. If you're paying for a three-phase supply then any upgraded head they install would be like-for-like in terms of functionality. You wouldn't be downgraded unless you decide you no longer need that kind of capacity, your physical wiring has been changed to no longer be split across phases and you request to be downgraded to save ongoing running costs.

[@stewartthorpe7159]

As a DNO jointer I often go to homes with 3 phase cut out that needs replacing . The answer to your question is replace like for like . Can't replace 3 phase to single phase internally , this would mean stubbing 2 phases within the cut out , which isn't an approved procedure !! Stubbing 2 phases externally within a joint and a single phase cable brought into the property would be required which is costly time consuming and disruptive .

[@Benzknees]

If there was no way of isolating the supply and you were changing a circuit board, what methods would you use to handle the live supply wire when disconnecting & reconnecting it to the circuit board?

[@dsesuk]

I personally believe anyone (sparkie or homeowner) should have the basic right to be able to make safe the tails, and I've pulled my share of fuses just like anyone else. If the DNO think fuse pulling is such a no-no, they should install service heads or smart meters with integral isolators. They've had the perfect opportunity too with the smart meter rollout that's going on, but they didn't bother so they shouldn't cry about these things. These days, I use an installer approved by the DNO to either pull the fuse or to install an isolator and I pass the cost on to the client. A fuse pull is, I think, £35, an isolator is £66 (plus VAT) (see hasteltd.co.uk). I think the isolator cost is low enough that the client shouldn't baulk at the price for the advantage of having the thing, but if they want to go with someone cheaper who will skip steps to keep down costs then that's their choice. It's not like I'm ever short of work.

[@Khanjan-si8me]

Nice one thank you i will love to see more of it....

[@gavinjohn-hyde2760]

SSE allow electricians registered with schemes such as NICEIC, NAPIT etc to pull the fuse on single phase domestic properties, if its old, stuck or 3 phase then call them out. SSE seem to be a rare DNO

[@Saaj2]

My friend at UKPN says the dno side is fused at 400 amps, but I guess many sparkies are happy risking themselves pulling the fuse as inconvienient it may be to call out the DNO

[@Berkeloid0]

Genuine question - what sort of risks are you exposing yourself to if the main switch in the consumer unit is off? There should be almost no load on the fuse, right?

[@munchingfoo]

@@Berkeloid0 For old fuses you could pull and break the plastic isolation exposing 400Amps of current at 240V on your fingers with your body being the quickest way to ground. For really old cut outs you could just make the entire thing explode into a million pieces. If there is a circuit fault on the cut out side of the CU with a fault current below the breaking current of the fuse then it may not be dead. Of course it is entirely possible to do it safely, otherwise the DNO couldn't even do it. There' a really good MOCOPA training video by SSE on you tube that shows the correct procedure for handling these circuits and the PPE required. Basic steps: visual inspection for damage (any damage means isolating further up the network before carrying out work in most cases). Isolate consumer side. Identify LNE visually and confirm via inductive detector. Dress up in your all in one safety condom. Pull fuse in a strong single movement. Prove dead. Remove condom. Carry out work. Adorn condom. Carry out tasks in reverse order.

[@retrocomputeruser]

I wonder how many electricians have swapped a consumer unit with the tails still live (conductor taped or something) because there is no isolator and doesn't have the time to arrange for a fuse pull.

[@coralbay00]

Many times. But with the new metal boards.....no thanks 🙏

[@davidmarsden8868]

That was a serious one

[@JohnSmith-ws7fq]

8:14 I think T was used because IEC 60364-1 is written in both French and English. The French word for earth is "terre" and it's used extensively in the document.

[@raver1481]

Shouldn't all CU's be fitted with a separate isolation switch?

[@pineappleroad]

In the UK there is often only a switch in the consumer unit itself, which is no good for turning off the power when the consumer unit needs to be changed our house doesnt have any way of isolating the power without pulling the fuse before the consumer unit, but weirdly enough, my sisters house (she lives next door, literallly next door) has an RCCB before the consumer unit, which can be used to turn off the power to the consumer unit if needed, only problem is that if a consumer unit upgrade was done, the RCCB (another term for an RCD) would become an issue, as there would be 2 RCDs protecting the same circuit, and there is no saying which would trip first

[@petehiggins33]

When my house had its first smart meter fitted a couple of years ago, by EoN they fitted a double pole isolator as a matter of routine, at no charge, so someone's getting the message. We're onto our third smart meter now due to changing suppliers and of course it's still smets1.

[@dsesuk]

No such luck here. Worse in fact, as my old Siemens meter had in integral isolator, but when EoN fitted my dumbass SMETS1 meter I was left without the ability to isolate the installation, without the ability for automatic meter reading when I left EoN a few months later and without the ability to see what my readings were without having to press buttons on the thing.

[@mrcrtking]

You should do one on earth loop Impedance and the fact that if its too high breakers won't trip, just done the BS7909 NAPT course, head fuck in 3 days, still we worked out on a long run of 1.5mm 3 core with short fault we could pull 77 amps for at least 5 seconds before breaker will trip, nice toasty cable! And type C breaker won't trip untill it sees 1600 amps, we run 250 & 125a 3 phase to distro unit and then run short and long legths of socapex, 16a cee forms, hoist control on delta, basically entire shows using massive LED screens, audio and projectors etc for live event, we now have to certify our work and take earth loop Impedance readings etc, also that PME can be lethal if neutral gets cut close to premises as earth will float at mains potential if loads are on

[@dsesuk]

Sounds like an interesting course. I hope there was a free bar at the end of it!

[@bjem2287]

Here in New Zealand the meter isolator (or main switch if upstream of the meter) is generally sealed. But I had an inspector come to change the meter and he told me the seal on the switch has no legal force. He also sealed a dustribution link for the live wires even though thats downstream of the meter too and also has no legal force. It left me scratching my head a bit. BTW the house was protected by a 63 amp fuse mounted out on the power pole in the street.

[@Berkeloid0]

I always thought the main reason for the seals was as evidence if they suspected the owner of tampering with the meter, rather than any sort of legal thing.

[@bjem2287]

@@Berkeloid0 True, but there are legal consequences of meter tampering. Makes my job easier, means I don't have to worry about having to cut main switch seals. It also explains why I've seen main switch seals not being changed when meters are changed (and re-sealed).

[@Berkeloid0]

@@bjem2287 Oh sure I just meant that if the supplier suspects the meter of having been tampered with, the onus is on them to prove it - so I think the seals help them do just that. I don't know if it's still the case, but the last time I had major electrical work done (many years ago here in Australia) the sparky just cut all the seals, did what he had to do (new CU, from fuses to breakers), then called the supplier and quoted an ID number when he was done. The next day the supplier came out and re-sealed everything and that was the end of that.

[@ykjump]

35 years of sparking and the only domestic properties that have an isolater are the 80's elcb which have been rare. Registerd sparks should be able to remove the fuse where no isolator exists. Its safety that comes first. Phase tape and gloves are not an option.

[@TheEulerID]

My house (built in 1996) has a single pole BS5419 isolator immediately after the meter in the external meter cabinet. However, it is fitted with seals. It was cruddy and wouldn't switch until sprayed with switch cleaner. Why some means of isolation isn't fitted as standard I don't know. The costs would surely have been insignificant if done at installation time.

[@MickeyBlue-eyes]

The supplier is responsible for the tails from the head to the meter.

[@ningis21]

Hi David.. BS 1361..... and BS88-3........ are they the same?

[@dsesuk]

The annoying thing about BS1361 is that they took the time curves out of the regs books in favour of BS88 which is daft. Okay, so BS1361 may have been superseded by BS88-3, but there's an awful lot of BS1361 fuses out there, so access to the time data is still useful! Anyway, I do have a BS1361 time curve graph and there's not a huge difference between it and the graph for BS88-3. The ratings are different in places, e.g. 60A for BS1361, 63A for BS88, and generally it seems the BS88 flavour will operate at a slightly lower fault current, but not by much. I've never researched why BS1361 fell out of favour, or if BS88 has any greater advantage in terms of manufacture or breaking capacity. Someone somewhere decided to standardise for whatever reason! Not that I get to play with either kind of fuse much, at least not unless it's at the lower end of the scale such as an old cartridge-based consumer unit with 5 /15/20/30A fuses for final circuits.

[@gordslater]

they chose Terra because they all watched Terrahawks as a kid. That's why the symbol for impedance is Z, for Zelda.

[@gordslater]

actually they chose Terra because the word Earth had already been used as a specific meaning, and so Terra is meant to represent the planet earth, as opposed to a human-made earth confuctor.

[@dsesuk]

Funnily enough, I remember Terrahawks and tried watching it again a few years ago with my youngest. It was appalling. Especially when they start singing.

[@richardwilliamson3624]

Another man with a Hager screwdriver!

[@the_real_hislordship]

Out of interest, why do they use fuses? Surely a similarly rated breaker would be better?

[@dsesuk]

I suspect it's down to lower costs but also that the moving parts of a breaker could seize over the decades or be deliberately jammed by some idiot trying to take more juice than he should. While a fuse can also be defeated by replacing it with a bit of copper pipe or similar, seals would have to be cut to gain access to it. I also suspect the supplier wants to know when their service has been overloaded and would prefer being called out to a fried fuse than have a hapless homeowner restore the power by flipping a breaker back on. If that overload device has gone, then there's a good reason possibly involving exceeding design demand, an attempt to fiddle the meter or a serious fault like shorted tails that someone needs to be looking into!

[@Monkey_slapping_keys]

Nice, house just purchased, I have a 60 amp with 16mm tails and no seals.

[@gordslater]

no problems with them stealing your fish then

[@gordslater]

and your beach balls will be safe

[@Monkey_slapping_keys]

@@gordslater Are you ok there champ?

[@liamjordan5935]

you've got someone to do hair and makeup in this video 📹 👀 🤪

[@Chimp_No_1]

Interesting and helpful. Thanks. New subscriber.

[@rochedihichem4697]

Thank you very much for this video

[@arslanelectration6306]

Good Sri

[@tyronethompson5670]

Hi David, I’m definitely one of those electricians who pulls fuses. I’m just curious as to how much haste charge to pull a fuse? And how you allow for that on a Consumer unit upgrade (costing £350-500?). What I’m getting at is doing it the anal (but correct way) may put your quotes way higher than the next electrician who would pull the fuse. Although very cheeky I have actually bought the metal crimp seals online and replace them every time.

[@dsesuk]

Hi Ty. Any sparkie who claims never to have pulled a fuse is probably a SODDING LIAR, but yeah, it'll always cost more to do it properly. Haste charge me £66 plus VAT for an isolator install, a cost I pass on to the client as a separate itemised part of the job. When it comes to CU changes, I'm not interested if the client wants it cheap or if I cannot do it properly. I always do a full EICR before the change (on a different date), I book Haste to install an isolator if necessary, then when all is ready I go in and do the physical swap. It means I'm not the cheapest, but it's one of those things I insist on doing my way.

[@DerekHundik]

with smart meters they'll know immediately when power is cut and they come on site in no time.

[@CAsCurryKitchen]

How will they know the power is cut?

[@DerekHundik]

@@CAsCurryKitchen sim card means connection is lost.

[@paulmorrey733]

Cheers

[@mastergx1]

To be honest, I made the decision a long time ago that I needed a third option. The first two options (cut the tag and remove the fuse myself or call the supplier out to do for me, then come back and replace it) were not acceptable. No-one has time for dicking around like that. My third option, and this will leave some clipboard warriors cringing, weak at the knees and short of breath, is to WORK LIVE. Now I'm not stupid. I know the dangers of what I'm doing and take extra precautions when I do this. Whenever I'm handing the live tail, I wear insulating electricians gloves (blow tested every time). On top of that, to avoid damaging the (rather expensive) gloves, I wear a pair of gardening gloves that resist sharp pokey things like thorns, splinters and badly cut live copper tails. In addition, I use a few layers of insulation tape on the conductor when inserting it into a new enclosure, removing the tape only when I'm just about to terminate. I deliberately avoid initially earthing any metal consumer unit to avoid an earth short if I do touch it. I don't want to blow the main fuse and my extremities are protected in case I touch the unit. Once the tail is terminated and confirmed secure, I can breath a sigh of relief and get on with the rest of the job.

[@thelifeofripple245]

Yes why would you do it that way??? I would risk being told off for pulling the fuse than risk my own health and safety... must also be a struggle feeding those tails through the dedicated glands with tape on the ends... hmmmm🤔

[@Porkchop259]

Why on earth would you work live. How many householders pay the slightest attention to if the cut out is sealed or not? most of them don't know what the cutout is. Meter readers don't pay any attention to weather the cutout is sealed. And when the energy company engineer comes to change the meter they don't really expect the cutout to be sealed as three quarters of them are unsealed anyway.