The main hazard with UK plugs is not an electrical one - if you drop one on the bedroom floor, it is guaranteed to land with the pins facing upwards. If you then step on it on your way to the bathroom in the middle of the night, it really, really hurts.

There's a reason Big Clive calls adapters with those kind of sockets "death-dapters".

One of the big "unseen" problems with those "universal" sockets is that the contact pressure of the contacts can be much lower than in the conventional sockets, which can mean arcing or heating when the contacts get older, because the contact pressure is part of the "self cleaning" part of the contact design. I suppose in this application this is less of an issue because of the low maximum current, but it still might cause problems in future with poor contacts and it definitely cause problems with the plugs not being secure when plugged in.

The UK plug also is designed that if the cable is yanked out of the plug housing itself, the live will be the first wire to disconnect. You can see that when you showed the fuse, brown is live and is the shortest wire in there.

We _need_ fused plugs in the UK because to save copper thanks to the war, we built our mains wiring in houses as a series of loops. These loop will carry much more current than the plugs are rated for because they power every outlet in that loop, so the circuit breaker for them is higher than the rated current of the plug. We have this additional fuse on the plug therefore to protect the wiring between the outlet and the appliance, although I like the idea of keeping them if we ever phased out rings completely.

"In 1984 BS1363 was amended with a requirement that the line and neutral pins should have an insulation sleeve."

Hi Noel. The earth wire should be at least as thick as the phase wires. Assuming it is not an isolated transformer.

Actually if you look at your "European" plugs ground, it also has a hole in it. On some sockets (I think at least in Denmark, but not in Norway where I'm from) the wall socket actually has a grounded "peg" sticking out, matching that hole. BTW: If you had rotated your inset 90degrees the angled plug would go in both ways, and cable management would get a nicer look and feel :)

As someone said, eath wire should be same gauge as main leads. I would check it (maybe it's just less of insulation, but that is also bad from mechanical standpoint). Also, dremel tip - if you can avoid standing in blade plane, avoid it. When your blade is horizontal, you cannot avoid it, unless it's over your head, which would be uncomfortable. Tipping transformer on the side would allow you to dremel top part without being on blade plane. I once had broken blade on dremel, that shit flys high speed, left ident on wooden closet doors, about 1*1,5 cm, 1 mm deep. It went almost parallel to doors, it would probably penetrate deeper if it was at 90°.

Noel I am worried the EARTH wires are very thin inside that transformer case. Please consider upgrading them. In France the Earth pin sticks out of the recessed socket and there is a hole in the plug not at the edges. Best wishes.

You’ll also notice that the top prong on the British plug is slightly longer. The two live holes won’t open until the top pin has triggered a release. Also why you can put a euro plug straight into a British socket with the help of a matchstick (probably not advisable though).

Northern Europe actually has 2 different socket designs that are partly compatible. One with 3 prongs and the one you have which is a german standard called schuko. Schuko has the recessed plugs and the small taps at the sides making it impossible to plug in non schuko plugs that are fully round. Look at extention cords at ikea sweden for examples.

That seemed like a very competent repair/upgrade. Well done.

Interesting video. Two comments though. 1. Grinding and metal shards around electrical stuff, iffy (should vacuum very very well when done.) 2. UK plug has another safety feature, and that is the ground has to be plugged in for the Live / Negative trapdoors to open so those pins can be inserted.

Great video! I love using my dremel on metal and the sparks make a great visual on camera!

Nice informative video as always. The British plug is a chunky boy but also the best designed of all I've seen.

Hey, Noel! I discovered your channel recently and I've been binging the hell out of it. Your content is top tier! I was waiting for a new video and here we are. ✌🏼😅

Most new construction in North America now requires tamper-resistant outlets, and I have seen some devices with a bit of insulation on the prongs. Meanwhile, your sockets do not appear to be polarized, so devices don’t have a consistent neutral. You really have to be careful with that in North America since older 2-prong devices could energize the casing if you somehow defeated the polarization and reversed the polarity. One example is the antique “Radiant” toaster Technology Connections fixed.

I'd be more inclined to install IEC C13 outlets in the transformer and then replace the native plugs on various power boards/bars/strips with C14 plugs.

Get a " nibbler " to make holes in sheet metal much safer.

I'd probably have used a "nibbling tool" to increase the size of those socket holes, but whatever works is good. The one thing I don't like about the new sockets is that ability to insert the plug either way around. This means that the "live" could be on either wire, which is only safe if the appliance has double-pole switching. Australian plugs and sockets are polarised and although there were "double adapters" which switched the live and neutral wires on one side, this was made illegal some time ago due to the safety issue. Australian plugs and sockets are not recessed, but the convention of adding insulation to the first half of the current-carrying prongs is becoming more popular. An Earth wire is mandatory unless the appliance can claim to be "double insulated" which means that there are at least two distinctive layers of insulation between the power wiring and any exposed metal. (Some appliances have no exposed metal and so can be unearthed)

Well done! It's not just the fun aspects of retro everyone here likes: Safety First. I"m so glad you caught this and corrected it.

I was in Thailand a few years ago, the hotel I stayed at had those death-dapters for *every wall socket*, it was certainly a thing. I mean it was convenient that I could just plug in my US plug switching power adapters into those 240V sockets but damn haha

Small correction: Short-to-earth situations are handled by a GFCI or RCD, which is a device that immediately breaks the circuit when it detects a difference between the outgoing and return current. Overcurrent protection alone isn't enough to prevent electrocution, as even a few tenths of an amp can be deadly at mains voltage.

7:29 That transformer looks like an autotransformer, as there is only one neutral wire. So that means the transformer has no isolation from the line input voltage. It is definitely appropriate here for the safety earth connections to go back to the line input connection. edit: The safety ground wiring is MASSIVELY under rated. It should definitely be the same thickness as the live conductors are. Also it doesn't look as if the metal chassis is grounded either. Typical corner cutting in Chinese made stuff.

A point which seems to be missed or misunderstood by many, is about the fact that UK plugs contain a fuse. Generally speaking, in the uk, when the gauge of wiring goes from one size to a thinner size, the fuse needs to be changed accordingly. For example, 5 square mm of copper can comfortably carry 32 amps at 240v, so sockets in the uk are often fused or more recently protected by a 32A MCB. BUT, when you plug in an appliance, say a table lamp, which might have say, a 0.5mm flexible cable, that cable Will melt, explode or cause a fire long before 32 amps of current flows along it, so when stepping from the heavier cable feeding the sockets, to the unknown cable connected to a plug, we have a lower value fuse, not least because the cable to the appliance is very very unlikely to be able to carry 32 amps. Unfortunately, selecting a suitable fuse value seems to be beyond many manufacturers these days, so I think that the only *common* fuse values now are 3 amps and 13 amps, but that's better than no fuse. Fortunately for me, I still have a small stock of 1A, 2A, 3A, 5A 10A and 13A fuses. 😀

12:18 if you had inserted the sockets with 5.5mm holes on top of each other, a 90 degree plug would fit easier. (Here in EU it is not at all uncommon to see Shuko sockets inserted in 45 degree angle, to ease the plethora of plug shapes including so called wall warts/ Rat tail power supplies.)

If I remember correctly, the genius of the UK plugs don't end there. Unless I'm mistaken, the hot, neutral and ground wire are, when correctly installed, supposed to disconnect from the plug in that order in case the cable gets tugged, stepped on or yanked on to the point where it comes out of the plug. Please correct me if I'm wrong!

the polish version of the eu socket has a third prong. But on the outlet and it goes into the standart hole on the eu plug in the middle.

Believe it not, prior to the current design, the UK used 3-pin plugs with round pins. These were available in 2 plug sizes. Small for things like lamps and radios that drew less than 5 amps and large for items up to 10 amps. Neither had a built-in fuse unlike the current design. Also, the UK plug has a longer earth pin so that it makes a connection before the live or neutral pins.

The sockets, you built in, were German sockets. The German plug have (sometimes), as shown here, a hole in the connection between the earth connectors. This is, so it can pushed in a french socket as well. Italian and Swiss sockets are also different from the german socket. You should search after the different types of European sockets. There are a few...

Also not mentioned - if you plug a NEMA 5-15 connector into the BS 1363 "universal" socket, the polarity is reverse. look @5:39 and you'll see L is on the left. In the upside down BS 1363 "universal" socket, that means L is on the left pin of a NEMA 5-15 plug - which is backwards. NEMA 5-15 plugs have L on the right and N on the left. I discovered this when doing safety checks on one of those 110v/230v step up/step down transformers exactly the same as in this video.

Hello Noel, you might want to add a nibbler to your toolbox...no sparks especially for sheetmetal enclosures.

Your points about the universal power connector are quite good. Yes, it is not safe as you demonstrated. But I would like to point out something you missed as to how electrical safety ground systems work - at least in North America. The ground wire or terminal is not simply connected to the Earth with a ground rod. It is also bonded to the neutral wire in the electrical system, universally at the building service entrance. This is what provides the shock or electrocution protection. Should the hot side of the line or mains touch the appliance metal case or chassis, that will be a short circuit to the neutral by virtue of the neutral to ground connection at the service panel and blow the fuse or trip the circuit breaker. Should the neutral wire of the mains or line touch the the case or chassis, no harm as it is at or a few safe volts above ground by virtue of the ground/neutral bond. This even works in the American split phase 120/240 residential system. The utility transformer split secondary is of such low impedance that either side of the split phase to ground will provide plenty of fault current to open a breaker or fuse*. Earth as a ground is only relevant in two cases, lightning and protection from it, and low frequency radio communication, AM, SW, and associated frequency bands. Other than that, the Earth ground is not required for any man-made electrical system to work. Think about it. Your cell phone has a lot of complex analog and digital electronics systems. Where is the Earth ground? A plane, car, space craft or probe? Where is the Earth ground? Earth ground in our electrical systems is for lightning protection and some forms of radio communication only. It serves no other purpose for safety. Grounding an electrical system without the neutral wire bond is in fact a safety and shock hazard. The American NEC recently (2008 IIRC), made a distinction between bonding and grounding as the two terms were being previously dangerously mis-applied. GFCI or the European equivalent RCID(?) provided added protection where a ground fault may not produce enough current flow or not quickly enough to trip a breaker or blow a fuse. That's another complex discussion as to how they work. * Note that in the USA we do have a problem with occasional open feeder neutral faults on split phase systems, so no, it's not perfect either.

Great idea , better than a dermal is a nipper . Would you be able to rotate the sockets 90* as not to block the sockets above ?

PE connectors actually weren't added to Schuko, they were there from the beginning. It actually pre-dates our current electrical system, back then they (meaning individual cities) tended to use a centre-tap with 220V between the phases and 110V phase to PE, standardisation to uniform 220V (and phasing out of 110V at least lights) came only after WWII. The socket design is mostly like it is because of manufacturing concerns back in the 1920s.

The dremel brings back memories. 2 years ago I built my computer. I wanted dual 360 mm radiators. But only 1 fit. It was VERY close. So I cut a hole to make it fit (which would be covered by the outer cover anyway). I used 3 dremel bits. And yes there were sparks.

were did you get a UK plug with no shielding on the pins Plus all uk three pin plugs are fused

5:21 Typed a comment mentioning the lack of sleeving on the pins, but you covered that. That will teach me to pause and comment straight away! 6:05 Also notice the live wire is the shortest wire on the most direct path? That's not an accident, it's so if the cable is ripped from the plug (say somebody tripping over it), the live wire would be disconnected first. The UK plug really is an incredible piece of design with so many carefully though out safety features. Sleeved pins to prevent contact, the earth pin being longest so it connects first / disconnects last, the safety shutters, individual fuses etc. Any attempt to make a list always results in forgetting something! And yet people criticise them for being bulky or other nonsense. Edit: And as if I could predict the future I've indeed found a comment here about the plugs being bulky. Idiots.

Good work! 🎄

Metal nippers, Noel! Though your dremel-freehand is certainly passable. 😀

Really nice work.

Thanks for the video. When you put the plug into the new socket upside down, does that change live and neutral? Does the machine change from 60hz to 50hz ? Just asking because I have never had to use a UK or Euro socket in Canada.

Have you seen the Brazilian wall plug standard? What you think about it?

The danger of north American plugs is overstated, in not entirely theoretical. I haven't heard of anyone being shocked when plugging something in unless something was in disrepair. Furthermore, tamper resistant sockets (required by code) have reduced the amount of exposed prong when energized to a 1/4" or less. Far too small for a finger. If that still makes you nervous because you like to drop uninsulated wires down the wall when you plug in your devices, you can rotate your outlets 90 degress so the neutral blade is on top.

3:40 "earth" leads are slightly more complicated. At least in the USA, "earth" is connected to a ground rod, but ALSO connected to neutral at the fuse panel. If the hot line shorts to the frame, the current will be carried by the "earth" wire from the appliance back to the fuse panel, but will continue along the neutral line. The actual "earth" connection to the grounding rod cannot carry very much current. Instead, it is there so there is no potential difference between neutral and the physical ground. For your toaster, a toaster with the frame connected to neutral would be just as safe from an internal short circuit. However, if you were barefoot (or otherwise had a good connection to the ground), and touched the frame, you would get a shock from whatever the potential difference is between the ground and the neutral. This is even if the appliance is functioning properly. That's why bonding ground and neutral are so important. It's also why you have to be very careful about connecting generators and inverters to fuse panels. If you don't know what you're doing, you could have a floating ground with a fair bit of potential difference from the actual ground.

Interesting! I've always wondered about those.

FYI a hand "nibbler" is a much quicker and cleaner way to make minor cuts on sheet metal like these.

Mains lines soldered and not crimped or screwed to outlets. This should be fun to watch in the future.

In re UK plugs and sleeved pins, it was added in the 1984 revision of the standard, the early BBC micros predate that.

meanwhile us in the USA: hey... that looks almost as safe as our plugs 2:40 "but wait!" .....why did i expect you to say "through the magic of buying 2 of them"??

There is a cheap hand tool called a nibbler for cutting sheet metal square holes on sheet metal

And If needed, you Can always use one of Those travel adapters, to convert directly from European to uk standard socket. With Ground and everything

With UK plugs it's also important to use the correct fuse value. A 13A fuse for a BBC Micro would be far to high. Probably 5A would be the best value to use 😉

Earth is also needed for over voltage protection to function properly. Many modern power supplies have varistors connected to ground, and ground is connected to metal body. So if there is no earth connection, potential of the chassis is somewhere between live and neutral. Being a varistor, current is low enough not to kill you, but high enough to fry electronics if your device is connected to grounded one. I learnt it hard way, when I had my PC connected to ungrounded plug, over HDMI to TV. When I connected cable TV to cable service, it got ground over cable, so my TV and GPU were dead.

Hola paisano Noel, acabo de descubrir tu canal y me encanta. No se si conoces el enchufe francés, es como el europeo pero la conexión a tierra la hace con un pibote/barra que sale del mismo enchufe/socket de la pared. De hecho verás que en la clavija hay un hueco donde ese pibote entraría. Lo que me gusta de ese enchufe es que al no ser reversible el neutro y la fase llegarán siempre al aparato tal y como éste fue diseñado, teniendo siempre el fusible en la fase. In english: Another interesting plug is the french one, the earth connection is don with a third pin and is not reversible, so the fuse will always be in the phase line

I find it strange that people don't know that our system here in North America is 240 volts. You can wire up 240 sockets. We do this already with Ovens and Dryers.

You linked the wrong TC video in the description. Still a good one for people to watch, but it's not the one you were referencing.

That is freaking nuts dood.

If the transformer inside really provides galvanic isolation, i.e. two separate coils, then you would have to touch both wires to get a shock. However, if it is a autotransformer with only one coil, there is no galvanic isolation and protective earth becomes a valuable asset again.

I have been using an UPS/inverter with this universal socket for years. The other day I made a heavy duty extension cord with 10 AWG wire and a GFCI outlet. I plugged it in and the GFCI tripped. I plugged in my little 3 light tester and that inverter universal socket has the hot /neutral reversed. WOW. I assumed that outlet was in parallel with it's hard wire connections. I had used the hard wire it into the camper's breaker box. The camper is old and only 120 volt. So if the camper is not plugged in, the UPS Inverter switches to the battery bank. I had wanted to run some stuff in my house with battery backup, so I had just plugged into the universal plug on the inverter instead of into the old wiring of the camper which I knew had tested correct when wired the hard wire terminals are correct but that universal socket is reversed.

That transformer does it output the correct frequency? ie 50HZ for 230v 60HZ for 120v? I've seen the technology connection episodes, will rewatch to refresh my memory.

The Uk plug has a fuse because it was designed for a ring final circuit which is connected to a huge fuse in the consumer unit so its absolutely necessary to have a fuse for each appliance. For a star final circuit the in plug fuse is less crucial since the fuse for the whole circuit is usually much smaller.

4:27 We also added the third thingy but on the socket instead of the plug

I realise you were targeting a Euro plug, but I think the Australian plug covers all of your safety concerns.

When you placed the power plug into the socket upside down. Does it matter that the Active and neutral are now reversed. Would that cause a issue with the internal fuses or not.

Adapters which convert EU sockets to UK ones are very tidy because the earth pin on the UK plug connects directly to the EU earth.

They didn't have too many screws for this design - those screws are holding the entire weight of the transformer. A better design would have the handle directly connected to the heavy part with the cover not being structural - or maybe some tabs to hold weight. But right now those screws are structural.

Would be pretty easy to put a schuko on the end of the cable for the bbc micro.

pasa de 120 v a 220 v , supongo que sera por estar en USA ? supongo , no afecta que sea 60 hz ?

Really good job.

You could make up a short lead with UK socket and EU plug btw the longer Earth pin on the later UK plugs also unlocks the safety shutter covering the neutral and live to open allowing the plug to befully inserted. Its a safety feature to prevent young children inserting things and getting an electric shock(BS 1363).

3:45 Electricity will go go to the ground, instead the ground wire is connected to the neutral wire and the electricity goes to the transformer which trips the breaker. The ground connection alone would not cause it. In some European countries the ground is not connected to the neutral and they require additional protection to make it safe. The European socket is cleverly designed. When something is counter-intuitive there likely is a good reason. The idea was to allow grounded plugs be used in living rooms where no ground potential was nearby so grounding was not needed. On the other hand if prevented use of ungrounded plugs in kitchens etc. where ground was near and ungrounded devices were possible. Adapters that try to cheat this are banned. Not that they were not used in the 1970s when there still were old type ungrounded devices. Europeans view the grounding on room basis whereas Americans view it on equipment basis. The US plugs do not provide that. You can put a hot chassis radio next to a grounded computer and create a death trap where pulling a knob on the radio when your leg touches the computer can kill you. In Europe either the computer is ungrounded or the plug of the radio does not fit. The fuse is because the breaker is 30 A on ring circuits. In the US or Europe one cannot put normal sockets on 30 A circuits.

My 520STFM originally shipped with EU plugs. I kept the original since 1989 in a protective bag and used the UK replacement ones since.

Actually some ground plugs in Denmark had the third ground leg, but otherwise it is standard european plug. Also it looks like a smiley face, since the ground leg is like a half circle

Not an electrician but have some idea on how electricity works. I would recommend checking the transformer for galvanic isolation, possibly by doing a continuity test between the terminals of neutral input and neutral output. If it is isolated then the earth terminal serves no purpose as no current will be flowing during a failure.

If you're in the US is there a reason why you're not getting 240v from the panel. If you put in the double pole breakers those give you 240 out. 240 volt US plugs are shaped differently so you can't plug in the wrong appliance. So you could just get proper US 240 volt to whatever plug standard you want.

I would have changed out the all red wires with the proper colors, like white for neutral, black for hot and green for ground...otherwise... great job.

For the BBC Micro, surely you could just replace the plug if available, or the whole lead if you can't just buy a European plug?

In an unrelated note, the US also uses 240VAC systems, but it's "split" into two virtual 120VAC lines, both deliberately put out of phase by 90 degrees. If we used the full 240VAC out of the gate... ...to put it plainly, all hell would break loose. Electrically speaking.

F-3000P transformer is autotransformer: Input neutral is directly connected to output neutral. Replace it with isolation transformer which hasn't high voltage referenced to earth at all. No high voltage risk - no "universal socket grounding" problem :)

I knew the two problems once I saw the thumbnail. That's something I really like the EU socket

On the Europlug notice the metal sheet with a hole in it on one side. This is because the plug design in places like the Czech Republic there is an earth pin sticking out of the recessed plug socket rather than metal pins on the side. Look up type E plugs for an example.

Take a look at sheet metal nibblers. They are perfect for what you used the dremel for.

I haven't watched the previous video yet but at least for the Amstrad it don't seem to hard to provide the needed power from a PSU. While I agree 100% on that its a good thing to change the sockets to proper earthed sockets wouldn't it still not be better to make or find a replacement PSU given that PSUs that old would be fairly likely to fail and possible destroying the whole computer if it fail?

European plug does have a third prong... See that hole between the prongs? It's a receptacle. That thing actually can connect to the prong in the outlet, which locks the orientation of the live and neutral prongs, but for some reason that outlet design is so rare that many don't even know it exists.

Noel, are you in the USA? Just thinking of the hertz, for screens etc

If the 90 degree angle of the plug is a problem, why not install the sockets rotated by 90 degrees?

Unfortunately there is one major oversight with this arrangement. IF the transformer is of the isolating type and not of the auto transformer type, adding an earth made no difference. With the isolating style of transformer, there is no electrical connection from primary to secondary, the primary being earth referenced via your neutral/earth bond at the switchboard. IF this unit has a single tapped winding (auto transformer) then the neutral/earth relationship remains intact and earth connection is important. With an isolated source, a malfunction in the appliance that makes the case live will not trip breakers or potentially even harm you because the 240V is floating. The upside to isolation is there is no shock risk with respect to earth, only via the two live conductors. Replacing those cheap plugs with the ones you used is a very good idea

i have a 'reversible' 240v to 120/120 to 240 'converter' that has one of those, ,and had only a 2 core input cable so although had an earth socket, no earth from the mains, i since 'improved' it fitting a IEC chassis input plug so standard IEC cable can be used, and as i will be the only one using it , and almost always in its 240 to 120 mode, its reasonably ok, for, the earth on european plugs problem i have a euro into UK adapter to go with it ... another issue with it and quite a few other 240 to 120 'converters' i came across is the common connection, which should be neutral was actually connected to the live, so the 120v out was one pole live to earth at 120v one 240v, the voltage between poles was the correct 120v but that 240v live pole could be a danger in some equipment, it may have parts only rated for 120v to earth inside... it was fairly easy to alter, BUT the live pin on USA 3 pin plugs and the one on UK plugs is opposite! its currently wire to be correct for UK plugs, as i thought best to be right for the high voltage output, although very unlikely i'd use it in 120 to 240 mode, you never know.... ..no easy way to make it correct for both.,

I've "buzzed" myself a number of times (U.S.) plugging things in where I can't see what I'm doing.

Sleeved pins didnt become mandatory on UK plugs till 1984, though they where common place before that date. It is the only update in the design of the plug that has been needed since it was introduced in 1947. Note the size of the plug makes it next to impossible to touch the pins of a partiality insert plug with your fingers even without sleeving. The sleeving is to protect against metals objects falling behing a partiality inserted plug, which is spectacular when it happens. Personally in your situation I would have just cut the UK plug on the BBC off (its not sleeved so needs to go anyway) and fitted a Schuko plug. Way less hassle than adapting to 120V IMHO.

Plug and Pray! .. especially when you try to use a CEE-7 (Europlug) with the 4.0mm prongs after you've inserted a Schuko-type (4.8mm). Proper European sockets are designed to handle this. Those death-daptor things (& the ones you show) are particularly useless with Australian plugs. We used death-daptors on our production lines with the same sort of hole & contact arrangement, since we made stuff for various international markets. Well, the other testers did, but I insisted on getting the proper sockets for each plug type for my test bay. It probably saved my life on a couple of occasions. Putting your hands in to attach probes right next to poorly-shielded mains connections ...

I use one for my laser cutter. I bought the wrong power supply when I built the laser. It was easier to use the transformer rather than wiring another 240v circuit to the machine.... I literally replaced the socket two days ago because the plug was so loose.

It is beyond my comprehension why on Earth this unit didn't come with sockets EXACTLY as you modified them, or one UK one on one side and the continental one on the other side. You are right about the US plugs being terrible. I don't know why in the US/CAN we haven't at least gone to a recessed one. Not using the Metric System also drives me crazy. All the Best! 73 DE W8LV BILL

Here in Japan it's even WORSE than in America because we use the American plug, but you'll usually NOT see the third, chunky pin. At most, some appliances that rely on earth have a CABLE, yes, one that you SCREW into a special screw found only in certain wall sockets designed for such appliances. It's absolutely dismal. Also, zero way of knowing if you're connecting the plug the wrong unless you have a way to measure noise. For the average joe, it doesn't matter, but ask people doing music production and they'll bore you tto hell and back here with how they had to spend HUGE amounts of money to install closed, specific isolated power cabling in their studios.

Replace the UK plug with a Schuko plug in that BBC Micro. No further modification required.

There is a variation of the 'schuko' socket with a prong sticking out. You might have noticed that the earth connection bracing in the plug has a hole in it. But I have only seen it on pictures a few times and while I'm working with electronics for 25 years and had a apprenticeship in the field.

Since I've done the same thing many times with a Dremel to mod different hardware, I'd recommend if it's only 2-3mm you're enlarging the hole, go with a grinding tip instead of a cutting wheel, and you'll come out with a much smoother edge on a single cut. Larger distances I still use the wheel first, but if it's under 3mm I'm grinding. You can get away with a pretty rough grain one, too, on steel cases like that or PC cases. Just a suggestion to make it come out nicely/easier next time! (It's also way easier to make tiny additions where the wheel would take too much off.) Edit: Granted, in this case it was a non-exposed cut edge, but if it is something people could ever touch, that saves a couple steps and time.

The hot glue is Silastic and it's there to reduce the chance of vibrational screw movement and protect against the ingress of water.