The standards the UK adopted pass higher voltages and higher currents per household circuit than pretty much anywhere else. They adopted standards that allow them to use use less wiring, less copper to provide the same energy. They can plug in many space heaters on one circuit, where two or three would blow a breaker on a US circuit.
That higher voltage and higher current makes their household circuits inherently more dangerous than household circuits outside the UK. A fault in a UK circuit passes a lot more energy than a similar fault elsewhere, before tripping a current-limiting device. The exact same fault in a UK circuit is far more dangerous than in a circuit pretty much anywhere else in the world. The standards for household wiring in the rest of the world are a lot more restrictive than the standards adopted in the UK.
UK plugs on Japanese appliance in Japanese houses (for example) are overkill. The safety provided by the UK plugs is built into the Japanese breaker panel and wiring. Putting the UK plug/socket into a Japanese circuit provides no significant additional safety benefit. The Japanese plug/socket on a UK circuit would be extraordinarily dangerous.
The higher voltage has nothing whatsoever to do with ring circuits. The UK runs on the same 220-240V AC as all of mainland Europe. And Africa. And most of mainland Asia. And South America. And Oceania. And most of the middle east. So not quite “higher than any other country”
Also those two claims are diametrically opposed to each other. Unless UK people use over twice the amount of electricity than Americans, the higher voltage will lead to LOWER total current. That’s quite literally the specific and sole motivating factor behind choosing a higher grid voltage.
And the current a conductor can pass has nothing whatsoever to do with it’s safety. You could have 50 amps blowing through a circuit, if it’s at 12V you can still touch it without getting a shock. Your car battery is capable of peak currents of several HUNDRED amps, and those are considered safe enough to just carry around by random people with bare hands.
Again, the amount of current passed depends only on the voltage, which again, is the same in the UK as all of mainland Europe (and most of the rest of the world except America and Japan), and has been since the early 20th century, so I’ve no idea what you’re trying to go on about there.
And lastly, no it isn’t. For one, the child safety shutters on all UK outlets are certainly not contained in a Japanese breaker panel. Neither are the fuses in the plug, which protect the external wiring. And nor is the insulation on the lower legs of the contacts contained in a breaker panel. The Japanese plugs are basically the same as American. You can literally get an electric shock if you hold them wrong whilst unplugging. There’s exposed live contacts from when you start unplugging until the prongs break their connection to the outlet.
Basically everything you said is demonstrably false. I’ve rarely seen someone be this confident and this incorrect about something.
Again, the amount of current passed depends only on the voltage
Electrically, current depends on voltage and resistance/impedance. In practice, (and most importantly to this discussion), current draw actually depends primarily on the characteristics of the current limiting devices such as breakers, fuses, etc. Breakers on UK household circuits are designed to allow considerably more power than comparable breakers around the world.
This is the primary factor I am talking about.
Neither are the fuses in the plug, which protect the external wiring.
Those fuses are not needed in Japanese (or North American, or most other) plugs. We don’t need to protect the “external wiring” separately from the household wiring: the household circuit breaker is rated lower than the “external wiring”. Drawing a direct short on the “external wiring” in a UK circuit is not sufficient to trip the UK circuit breaker in the UK distribution panel; they need a secondary current limiter (a fuse) to provide that function.
We don’t need fuses in our plugs, specifically because our household circuit breakers are designed to trip well before your fuses would blow. (We do include fuses in any appliance or device with wiring not rated to full current.)
And lastly, no it isn’t. For one, the child safety shutters on all UK outlets are certainly not contained in a Japanese breaker panel.
The function provided by those shutters is achieved in the Japanese wiring by lower voltage, narrow holes in receptacles (allowable because they don’t need as large a contact to safely carry the lower rated current), a flared base on plugs, protective accessories for outlets in risky locations, and whole-house AFCI/GFCI.
Breakers on UK household circuits are designed to allow considerably more power than comparable breakers around the world.
That is utterly irrelevant. Circuit breakers and fuses are designed for the exclusive and sole purpose of protecting the circuit from being overloaded. A 100 amp circuit with a 100 Amp fuse is exactly as safe as a 20 amp circuit with a 20 amp fuse or a 5 amp circuit with a 5 amp fuse. If the voltage is above ~100-200V, all 3 of these are hundreds of times the amount of current it would take to deliver a fatal electric shock, and none of those fuses would trip from you getting shocked.
To protect humans from electric shock we use residual current devices, which trip at 10’s of Milli amps. And here’s actually an advantage of a ring circuit. It forces you to place RCD protection on every single outlet in the building, instead of skimping on costs by just putting it on the branches that legally require one, like bathrooms and kitchens.
Those fuses are not needed in Japanese (or North American, or most other) plugs. We don’t need to protect the “external wiring” separately from the household wiring: the household circuit breaker is rated lower than the “external wiring”. Drawing a direct short on the “external wiring” in a UK circuit is not sufficient to trip the UK circuit breaker in the UK distribution panel; they need a secondary current limiter (a fuse) to provide that function.
That’s just demonstrably untrue. An individual branch of a household circuits in both the US or Japan can easily be fused at 20A (fun fact: European branch circuis, because of the higher voltage that you were raging against in your first comment, can handle more electric load whilst having SMALLER 16A breakers). In both Japan and America you can buy extension cords rated for 10 or 15A. So no. You just told a straight up, unequivocal lie there.
And a dead short on a 240V network will literally trip everything. UK ring circuits are fused at 30 Amps. A dead short at 240V with only the internal resistance of copper wiring would pull current in the neighborhood of 1000 amps. 1000, somewhat famously, being slightly larger than 30, making this another lie there.
And even if it weren’t a lie, how on earth does the location of the fuse make a difference in safety here ? If it’s in the wall or in the plug, as long as it’s there and does it’s job both would be equally safe.
The function provided by those shutters is achieved in the Japanese wiring by lower voltage, narrow holes in receptacles (allowable because they don’t need as large a contact to safely carry the lower rated current) and whole-house AFCI/GFCI.
No it isn’t. 110V is still dangerous to a child, and if you think otherwise I hope to god you aren’t, or ever become a parent. Also, as I stated, your plugs literally allow for an electric shock to happen whilst unplugging them because they’re so terrible. As for whole house GFCI, that is by necessity included in a ring circuit that wants GFCI on any outlet at all.
Also you seem to fundamentally misunderstand the relationship of current and voltage. For a given electrical appliance, with a given wattage, a lower voltage means it needs to draw more current, not less. That’s why the US Japan need to have 20A household breakers, whereas in the EU 16A branches are more than enough, whilst still providing a higher load handling capability than a 20A Japanese fuse. A 1000 Watt microwave plugged into a Japanese socket will draw over twice as much current as a 1000 Watt microwave plugged into an EU or UK socket (which also means it produces 4 times the amount of electrical waste energy as heat, though that is generally negligible for short household cable runs either way. Can make a difference on the scale of a country though).
And don’t think I didn’t notice you just quietly avoided responding to any of my arguments pointing out the obvious falsehoods in your voltage claim.
Frankly, at this point, all you’ve done is utterly convince me that you are totally and utterly unqualified to speak on this topic. Almost every claim you make is wrong. And not even just “slightly oversimplified/technically incorrect” wrong, just straight up demonstrably untrue.
That is utterly irrelevant. Circuit breakers and fuses are designed for the exclusive and sole purpose of protecting the circuit from being overloaded. A 100 amp circuit with a 100 Amp fuse is exactly as safe as a 20 amp circuit with a 20 amp fuse.
Stick your finger in a 20A outlet, and you’ll pull out a burned finger. Stick your finger in a 100A outlet, and you’ll lose your hand, or your life. More power will pass through you before the circuit can be interrupted.
To protect humans from electric shock we use residual current devices, which trip at 10’s of Milli amps. And here’s actually an advantage of a ring circuit. It forces you to place RCD protection on every single outlet in the building, instead of skimping on costs by just putting it on the branches that legally require one, like bathrooms and kitchens.
The power standards that created the need for UK plugs were developed long before RCD/AFCI/GFCI protections were adopted. Those later protections did not influence the decision to use that plug design.
That’s just demonstrably untrue. An individual branch of a household circuits in both the US or Japan can easily be fused at 20A
Our appliance wiring is rated to carry 20A from the receptacle throughout the appliance, or to a secondary current limiter within the appliance. Since the wiring is rated to the 20A the circuit can provide, we don’t need the secondary fuse in the plug. This is part of our appliance wiring standards.
And even if it weren’t a lie, how on earth does the location of the fuse make a difference in safety here ? If it’s in the wall or in the plug, as long as it’s there and does it’s job both would be equally safe.
If you have a 30A outlet, and you plug a cord rated to 20A into it, that cord will be overloaded before drawing 30A. Which means a fault in the appliance might not be capable of tripping the 30A breaker. For safety, you would need the cord to be rated to 30A to ensure the breaker will trip. The UK doesn’t use 30A cords on appliances that only need 2A of protection. They put a 2A fuse in their plug, and use a cord capable of surviving a 2A fault. (In practice, UK cords have about the same rating as US cords; a 20A fuse in the plug would suffice.)
Our breakers are rated at 15 or 20A. We require our cords have to be rated to be able to survive 20A without catching fire for long enough to trip a 20A breaker, even if the device is only expected to draw 2A. We don’t need the secondary current limiter, as the circuit breaker is designed and intended to trip before a fault allows the appliance to catch fire.
In both Japan and America you can buy extension cords rated for 10 or 15A. So no.
Different rating. An extension cord rated for carrying 10A continuously will still survive a 20A fault. The voltage drop through that cord will be out of spec, which is why it is only rated to 10A.
fun fact: European branch circuis, because of the higher voltage that you were raging against in your first comment, can handle more electric load whilst having SMALLER 16A breakers)
Obviously. That has been part of my point the entire time: You use fewer, higher wattage circuits. UK circuits carries more power to pass through your body than a comparable circuit elsewhere in the world. The household wiring standards in the rest of the world are more restrictive than they are in the UK. You are repeating the exact points that I (and others) have been making from the start.
UK ring circuits are fused at 30 Amps.
30A @ 240V in the UK. 16A @220V in the EU. 15/20A @ 120V in North America. 20A @ 100V in Japan. Keep those numbers in mind, assume someone is touching a live wire sticking out of their wall, drop the attitude, and re-read my comments from the very start.
Stick your finger in a 20A outlet, and you’ll pull out a burned finger. Stick your finger in a 100A outlet, and you’ll lose your hand, or your life. More power will pass through you before the circuit can be interrupted
Did you just deliberately ignore everything I wrote ? Both 20 and 100amps are several hundred times more current than it needs takes to kill you. And the resistance of your body is way to high to pass more than a few hundred milliamps anyway.
For a given voltage, the outcome of recieving a shock on a 20A fused circuit is literally indistinguishable and fully identical to that of receiving a shock on a 100A fused circuit. Identical. Literally.
Our appliance wiring is rated to carry 20A from the receptacle throughout the appliance, or to a secondary current limiter within the appliance. Since the wiring is rated to the 20A the circuit can provide, we don’t need the secondary fuse in the plug. This is part of our appliance wiring standards.
No it isn’t. I literally just told you you can buy 15A rated extension cords in Japan in the comment you’re replying to. 15, is in fact less than 20, just fyi. Are you deliberately ignoring half of what I wrote ?
Obviously. That has been part of my point the entire time: You use fewer, higher wattage circuits. UK circuits carries more power to pass through your body than a comparable circuit elsewhere in the world. The household wiring standards in the rest of the world are more restrictive than they are in the UK. You are repeating the exact points that I (and others) have been making from the start.
Wrong. Again. The current limit imposed by the internal resistance of your body at voltages in the range of 100-200 is a few hundred milliamps. Maybe an amp or two if you stick electrodes inside yourself, and anything higher than 100 mA going through your heart is already lethal anyway. You’re gonna be dead 200 times over waiting for your 20A fuse to save you. The power that will pass through your body depends exclusively and solely on the voltage. The capacity and fusing of the circuit is utterly irrelevant, unless it’s fused at like 40 MILLI amps.
UK ring circuits are fused at 30 Amps.
Man I fucking love how you literally just picked out the first line in a comment pointing out another one of the things you said that are objectively untrue (a dead short not blowing a UK ring fuse) and ignore everything else in the comment. You must have seen the comment to quote part of it, and yet you ignore it entirely. You’re clearly and demonstrably not arguing in good faith.
Reread my comments from the start
That’s fucking rich, when I’ve literally explicitly addressed every single point you made, whilst you seemingly deliberately ignore half the ones I make. Literally repeating falsehoods I disproved in the comment you’re replying to, whilst you’re replying.
No it isn’t. I literally just told you you can buy 15A rated extension cords in Japan in the comment you’re replying to. 15, is in fact less than 20, just fyi. Are you deliberately ignoring half of what I wrote ?
I covered that. Different rating. That 15A cord will survive a 20A fault. Its rated at 15A because the voltage drop will be out of spec at 20A draw, not because it will be a fire hazard at 20A. You will be able to get enough current through that 15A cord to trip the 20A breaker. You might not be able to get 20A through a 5A cord before the cord catches fire.
My point is that UK appliances are specifically not designed to trip UK breakers in a fault. US devices are.
In every jurisdiction where fuses are not required in plugs, appliance standards require the appliance to be able to trip the household breaker. This is a fundamental concept of electrical safety.
And the resistance of your body is way to high to pass more than a few hundred milliamps anyway.
That’s actually false. You’re conflating the resistance of “skin” with the resistance if the “body”. Once you burn away that skin, your internal resistance drops substantially.
I covered that. Different rating. That 15A cord will survive a 20A fault. Its rated at 15A because the voltage drop will be out of spec at 20A draw, not because it will be a fire hazard at 20A. You will be able to get enough current through that 15A cord to trip the 20A breaker. You might not be able to get 20A through a 5A cord before the cord catches fire.
ANY cable being driven above it’s rated load is a fire hazard. There healthy margins in those ratings, so going slightly over is likely not going to have any affect, but those margins are for good reason (namely people like you thinking it’s fine to plug a 15A cable into a 20A circuit without external fusing or current limiting), and deliberately overloading any part of an electric circuit is ALWAYS dangerous and stupid. And what about 7A cables you can get in japan ? you can explicitly get 0.75mm² cables, which are only rated to 7Amps. Just as confident of blasting 20A through those ? Almost 9 times the amount of waste heat being generated in the core than at it’s max rated load.
My point is that UK appliances are specifically not designed to trip UK breakers in a fault. US devices are.
In every jurisdiction where fuses are not required in plugs, appliance standards require the appliance to be able to trip the household breaker. This is a fundamental concept of electrical safety.
Nope, again completely untrue. Breakers are only required to trip if the circuit becomes overloaded.
Your breakers don’t, and can’t give a shit about what’s happening on the other side of the outlet.
Your device could slowly be melting itself into a pile of burning plastic, as long as it’s drawing less than 16 Amps to do so, the breakers will not trip. As I’ve pointed out, repeatedly already, and you have repeatedly ignored, breakers are solely and exclusively for protecting the wire from overheating /overloading.
And in fact, the fused plugs actually make it way MORE likely for something to trip on a device side fault in the UK, because the current only has to be like 3Amps to kill the fuse. In every other place of the world, current needs to be at least 16A before anything trips.
That’s actually false. You’re conflating the resistance of “skin” with the resistance if the “body”. Once you burn away that skin, your internal resistance drops substantially.
I address that point, quite literally, in a later a paraph where I write
Maybe an amp or two if you stick electrodes inside yourself
So what happened here ? Did you not read my comment ? Did you not understand it ? Or did you read it understand, and then continue to pretend like I haven’t already explicitly addressed this anyway ?
At this point I think calling this behaviour accidental would be an insult to your intelligence, and just have assume that you know exactly what you’re doing, and are knowingly and deliberately arguing in bad faith and with intellectually dishonesty, so stop. Just go away. I’m done. You’re either fully incapable of, or unwilling too, engage in honest debate, so I’m not linger interested in continuing this.
Nope, again completely untrue. Breakers are only required to trip if the circuit becomes overloaded.
Breakers are only required to trip if the circuit is overloaded. That part is correct.
The internal resistance of drastically undersized wiring may not be capable of passing sufficient current to overload the household breaker. And yet, pretty much the entire world (except the UK) doesn’t require fuses on their plugs. The unfused power cords for those non-UK appliances are either a fire hazard OR those cords are required to be able to carry sufficient current to trip the current limiter without catching fire. The latter is, indeed, the case. This is a big part of UL, CSA, CE, and other electrical certification standards around the world.
(namely people like you thinking it’s fine to plug a 15A cable into a 20A circuit without external fusing or current limiting),
That’s actually part of NEC code applicable in the US and Canada, and I’m not going to delve too far into it, as it really pisses me off. Basically, there is no functional difference between our 15A and 20A components. The standards needed for a component to carry 15A in North America are the same as the standards needed for it to carry 20A. Effectively, our 15A components have a safety margin 5A greater than that of our 20A components.
The historic and technical distinctions for this are well outside the scope of this discussion, and I think it is, indeed, moronic. But yes, technically, we can indeed use certain 15A-rated components on a circuit protected by a 20A breaker.
And in fact, the fused plugs actually make it way MORE likely for something to trip on a device side fault in the UK, because the current only has to be like 3Amps to kill the fuse. In every other place of the world, current needs to be at least 16A before anything trips.
Here again, you’re demonstrating my exact point, despite claiming that what I am saying is “completely untrue”: The rest of the world builds its appliances to tolerate at least that 16A fault. For the UK to use that exact same manner of protection, they would need to build their appliances to tolerate a 30A fault. The same appliance would need a much heavier power cord in the UK than in the EU.
Since no rational person would want to overbuild each and every appliance to be able to tolerate a 30A fault, they included a fuse in their plug. That plug, unneeded in the rest of the world, is an essential component in the UK. That plug is what allows the UK to be able to safely use the world’s 16A appliances on UK 30A breakers.
(No, the rest of the world doesn’t need 16A before “anything” trips. The rest of the world includes their fuses inside the appliance, immediately after the cord rather than on the plug end.)
The standards the UK adopted pass higher voltages and higher currents per household circuit than pretty much anywhere else. They adopted standards that allow them to use use less wiring, less copper to provide the same energy. They can plug in many space heaters on one circuit, where two or three would blow a breaker on a US circuit.
That higher voltage and higher current makes their household circuits inherently more dangerous than household circuits outside the UK. A fault in a UK circuit passes a lot more energy than a similar fault elsewhere, before tripping a current-limiting device. The exact same fault in a UK circuit is far more dangerous than in a circuit pretty much anywhere else in the world. The standards for household wiring in the rest of the world are a lot more restrictive than the standards adopted in the UK.
UK plugs on Japanese appliance in Japanese houses (for example) are overkill. The safety provided by the UK plugs is built into the Japanese breaker panel and wiring. Putting the UK plug/socket into a Japanese circuit provides no significant additional safety benefit. The Japanese plug/socket on a UK circuit would be extraordinarily dangerous.
The higher voltage has nothing whatsoever to do with ring circuits. The UK runs on the same 220-240V AC as all of mainland Europe. And Africa. And most of mainland Asia. And South America. And Oceania. And most of the middle east. So not quite “higher than any other country”
Also those two claims are diametrically opposed to each other. Unless UK people use over twice the amount of electricity than Americans, the higher voltage will lead to LOWER total current. That’s quite literally the specific and sole motivating factor behind choosing a higher grid voltage.
And the current a conductor can pass has nothing whatsoever to do with it’s safety. You could have 50 amps blowing through a circuit, if it’s at 12V you can still touch it without getting a shock. Your car battery is capable of peak currents of several HUNDRED amps, and those are considered safe enough to just carry around by random people with bare hands.
Again, the amount of current passed depends only on the voltage, which again, is the same in the UK as all of mainland Europe (and most of the rest of the world except America and Japan), and has been since the early 20th century, so I’ve no idea what you’re trying to go on about there.
And lastly, no it isn’t. For one, the child safety shutters on all UK outlets are certainly not contained in a Japanese breaker panel. Neither are the fuses in the plug, which protect the external wiring. And nor is the insulation on the lower legs of the contacts contained in a breaker panel. The Japanese plugs are basically the same as American. You can literally get an electric shock if you hold them wrong whilst unplugging. There’s exposed live contacts from when you start unplugging until the prongs break their connection to the outlet.
Basically everything you said is demonstrably false. I’ve rarely seen someone be this confident and this incorrect about something.
Electrically, current depends on voltage and resistance/impedance. In practice, (and most importantly to this discussion), current draw actually depends primarily on the characteristics of the current limiting devices such as breakers, fuses, etc. Breakers on UK household circuits are designed to allow considerably more power than comparable breakers around the world.
This is the primary factor I am talking about.
Those fuses are not needed in Japanese (or North American, or most other) plugs. We don’t need to protect the “external wiring” separately from the household wiring: the household circuit breaker is rated lower than the “external wiring”. Drawing a direct short on the “external wiring” in a UK circuit is not sufficient to trip the UK circuit breaker in the UK distribution panel; they need a secondary current limiter (a fuse) to provide that function.
We don’t need fuses in our plugs, specifically because our household circuit breakers are designed to trip well before your fuses would blow. (We do include fuses in any appliance or device with wiring not rated to full current.)
The function provided by those shutters is achieved in the Japanese wiring by lower voltage, narrow holes in receptacles (allowable because they don’t need as large a contact to safely carry the lower rated current), a flared base on plugs, protective accessories for outlets in risky locations, and whole-house AFCI/GFCI.
That is utterly irrelevant. Circuit breakers and fuses are designed for the exclusive and sole purpose of protecting the circuit from being overloaded. A 100 amp circuit with a 100 Amp fuse is exactly as safe as a 20 amp circuit with a 20 amp fuse or a 5 amp circuit with a 5 amp fuse. If the voltage is above ~100-200V, all 3 of these are hundreds of times the amount of current it would take to deliver a fatal electric shock, and none of those fuses would trip from you getting shocked.
To protect humans from electric shock we use residual current devices, which trip at 10’s of Milli amps. And here’s actually an advantage of a ring circuit. It forces you to place RCD protection on every single outlet in the building, instead of skimping on costs by just putting it on the branches that legally require one, like bathrooms and kitchens.
That’s just demonstrably untrue. An individual branch of a household circuits in both the US or Japan can easily be fused at 20A (fun fact: European branch circuis, because of the higher voltage that you were raging against in your first comment, can handle more electric load whilst having SMALLER 16A breakers). In both Japan and America you can buy extension cords rated for 10 or 15A. So no. You just told a straight up, unequivocal lie there. And a dead short on a 240V network will literally trip everything. UK ring circuits are fused at 30 Amps. A dead short at 240V with only the internal resistance of copper wiring would pull current in the neighborhood of 1000 amps. 1000, somewhat famously, being slightly larger than 30, making this another lie there.
And even if it weren’t a lie, how on earth does the location of the fuse make a difference in safety here ? If it’s in the wall or in the plug, as long as it’s there and does it’s job both would be equally safe.
No it isn’t. 110V is still dangerous to a child, and if you think otherwise I hope to god you aren’t, or ever become a parent. Also, as I stated, your plugs literally allow for an electric shock to happen whilst unplugging them because they’re so terrible. As for whole house GFCI, that is by necessity included in a ring circuit that wants GFCI on any outlet at all.
Also you seem to fundamentally misunderstand the relationship of current and voltage. For a given electrical appliance, with a given wattage, a lower voltage means it needs to draw more current, not less. That’s why the US Japan need to have 20A household breakers, whereas in the EU 16A branches are more than enough, whilst still providing a higher load handling capability than a 20A Japanese fuse. A 1000 Watt microwave plugged into a Japanese socket will draw over twice as much current as a 1000 Watt microwave plugged into an EU or UK socket (which also means it produces 4 times the amount of electrical waste energy as heat, though that is generally negligible for short household cable runs either way. Can make a difference on the scale of a country though).
And don’t think I didn’t notice you just quietly avoided responding to any of my arguments pointing out the obvious falsehoods in your voltage claim.
Frankly, at this point, all you’ve done is utterly convince me that you are totally and utterly unqualified to speak on this topic. Almost every claim you make is wrong. And not even just “slightly oversimplified/technically incorrect” wrong, just straight up demonstrably untrue.
Stick your finger in a 20A outlet, and you’ll pull out a burned finger. Stick your finger in a 100A outlet, and you’ll lose your hand, or your life. More power will pass through you before the circuit can be interrupted.
The power standards that created the need for UK plugs were developed long before RCD/AFCI/GFCI protections were adopted. Those later protections did not influence the decision to use that plug design.
Our appliance wiring is rated to carry 20A from the receptacle throughout the appliance, or to a secondary current limiter within the appliance. Since the wiring is rated to the 20A the circuit can provide, we don’t need the secondary fuse in the plug. This is part of our appliance wiring standards.
If you have a 30A outlet, and you plug a cord rated to 20A into it, that cord will be overloaded before drawing 30A. Which means a fault in the appliance might not be capable of tripping the 30A breaker. For safety, you would need the cord to be rated to 30A to ensure the breaker will trip. The UK doesn’t use 30A cords on appliances that only need 2A of protection. They put a 2A fuse in their plug, and use a cord capable of surviving a 2A fault. (In practice, UK cords have about the same rating as US cords; a 20A fuse in the plug would suffice.)
Our breakers are rated at 15 or 20A. We require our cords have to be rated to be able to survive 20A without catching fire for long enough to trip a 20A breaker, even if the device is only expected to draw 2A. We don’t need the secondary current limiter, as the circuit breaker is designed and intended to trip before a fault allows the appliance to catch fire.
Different rating. An extension cord rated for carrying 10A continuously will still survive a 20A fault. The voltage drop through that cord will be out of spec, which is why it is only rated to 10A.
Obviously. That has been part of my point the entire time: You use fewer, higher wattage circuits. UK circuits carries more power to pass through your body than a comparable circuit elsewhere in the world. The household wiring standards in the rest of the world are more restrictive than they are in the UK. You are repeating the exact points that I (and others) have been making from the start.
30A @ 240V in the UK. 16A @220V in the EU. 15/20A @ 120V in North America. 20A @ 100V in Japan. Keep those numbers in mind, assume someone is touching a live wire sticking out of their wall, drop the attitude, and re-read my comments from the very start.
Did you just deliberately ignore everything I wrote ? Both 20 and 100amps are several hundred times more current than it needs takes to kill you. And the resistance of your body is way to high to pass more than a few hundred milliamps anyway.
For a given voltage, the outcome of recieving a shock on a 20A fused circuit is literally indistinguishable and fully identical to that of receiving a shock on a 100A fused circuit. Identical. Literally.
No it isn’t. I literally just told you you can buy 15A rated extension cords in Japan in the comment you’re replying to. 15, is in fact less than 20, just fyi. Are you deliberately ignoring half of what I wrote ?
Wrong. Again. The current limit imposed by the internal resistance of your body at voltages in the range of 100-200 is a few hundred milliamps. Maybe an amp or two if you stick electrodes inside yourself, and anything higher than 100 mA going through your heart is already lethal anyway. You’re gonna be dead 200 times over waiting for your 20A fuse to save you. The power that will pass through your body depends exclusively and solely on the voltage. The capacity and fusing of the circuit is utterly irrelevant, unless it’s fused at like 40 MILLI amps.
Man I fucking love how you literally just picked out the first line in a comment pointing out another one of the things you said that are objectively untrue (a dead short not blowing a UK ring fuse) and ignore everything else in the comment. You must have seen the comment to quote part of it, and yet you ignore it entirely. You’re clearly and demonstrably not arguing in good faith.
That’s fucking rich, when I’ve literally explicitly addressed every single point you made, whilst you seemingly deliberately ignore half the ones I make. Literally repeating falsehoods I disproved in the comment you’re replying to, whilst you’re replying.
I covered that. Different rating. That 15A cord will survive a 20A fault. Its rated at 15A because the voltage drop will be out of spec at 20A draw, not because it will be a fire hazard at 20A. You will be able to get enough current through that 15A cord to trip the 20A breaker. You might not be able to get 20A through a 5A cord before the cord catches fire.
My point is that UK appliances are specifically not designed to trip UK breakers in a fault. US devices are.
In every jurisdiction where fuses are not required in plugs, appliance standards require the appliance to be able to trip the household breaker. This is a fundamental concept of electrical safety.
That’s actually false. You’re conflating the resistance of “skin” with the resistance if the “body”. Once you burn away that skin, your internal resistance drops substantially.
ANY cable being driven above it’s rated load is a fire hazard. There healthy margins in those ratings, so going slightly over is likely not going to have any affect, but those margins are for good reason (namely people like you thinking it’s fine to plug a 15A cable into a 20A circuit without external fusing or current limiting), and deliberately overloading any part of an electric circuit is ALWAYS dangerous and stupid. And what about 7A cables you can get in japan ? you can explicitly get 0.75mm² cables, which are only rated to 7Amps. Just as confident of blasting 20A through those ? Almost 9 times the amount of waste heat being generated in the core than at it’s max rated load.
Nope, again completely untrue. Breakers are only required to trip if the circuit becomes overloaded.
Your breakers don’t, and can’t give a shit about what’s happening on the other side of the outlet.
Your device could slowly be melting itself into a pile of burning plastic, as long as it’s drawing less than 16 Amps to do so, the breakers will not trip. As I’ve pointed out, repeatedly already, and you have repeatedly ignored, breakers are solely and exclusively for protecting the wire from overheating /overloading.
And in fact, the fused plugs actually make it way MORE likely for something to trip on a device side fault in the UK, because the current only has to be like 3Amps to kill the fuse. In every other place of the world, current needs to be at least 16A before anything trips.
I address that point, quite literally, in a later a paraph where I write
So what happened here ? Did you not read my comment ? Did you not understand it ? Or did you read it understand, and then continue to pretend like I haven’t already explicitly addressed this anyway ?
At this point I think calling this behaviour accidental would be an insult to your intelligence, and just have assume that you know exactly what you’re doing, and are knowingly and deliberately arguing in bad faith and with intellectually dishonesty, so stop. Just go away. I’m done. You’re either fully incapable of, or unwilling too, engage in honest debate, so I’m not linger interested in continuing this.
Breakers are only required to trip if the circuit is overloaded. That part is correct.
The internal resistance of drastically undersized wiring may not be capable of passing sufficient current to overload the household breaker. And yet, pretty much the entire world (except the UK) doesn’t require fuses on their plugs. The unfused power cords for those non-UK appliances are either a fire hazard OR those cords are required to be able to carry sufficient current to trip the current limiter without catching fire. The latter is, indeed, the case. This is a big part of UL, CSA, CE, and other electrical certification standards around the world.
That’s actually part of NEC code applicable in the US and Canada, and I’m not going to delve too far into it, as it really pisses me off. Basically, there is no functional difference between our 15A and 20A components. The standards needed for a component to carry 15A in North America are the same as the standards needed for it to carry 20A. Effectively, our 15A components have a safety margin 5A greater than that of our 20A components.
The historic and technical distinctions for this are well outside the scope of this discussion, and I think it is, indeed, moronic. But yes, technically, we can indeed use certain 15A-rated components on a circuit protected by a 20A breaker.
Here again, you’re demonstrating my exact point, despite claiming that what I am saying is “completely untrue”: The rest of the world builds its appliances to tolerate at least that 16A fault. For the UK to use that exact same manner of protection, they would need to build their appliances to tolerate a 30A fault. The same appliance would need a much heavier power cord in the UK than in the EU.
Since no rational person would want to overbuild each and every appliance to be able to tolerate a 30A fault, they included a fuse in their plug. That plug, unneeded in the rest of the world, is an essential component in the UK. That plug is what allows the UK to be able to safely use the world’s 16A appliances on UK 30A breakers.
(No, the rest of the world doesn’t need 16A before “anything” trips. The rest of the world includes their fuses inside the appliance, immediately after the cord rather than on the plug end.)
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