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 going through your heart is lethal anyway. 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.
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 going through your heart is lethal anyway. 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.
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