Current takes all paths. The element has actually lower resistance. A 3 kW kettle has just 19.2 ohms. However, while the kettle uses 13 A, only 0.1 A can kill. Also the wire can get completely loose so that it does not connect to the heating element. The earth wire does not go to the earth on a TN system. It goes to the transformer via a copper connection. On a TT system it goes to the earth but then the resistance is so high that it does not blow the fuse. On TT one must have an RCD to make it safe. One should abandon the term "earth wire" and use the proper term the CPC (The circuit protective conductor). That tells what it does without giving false implications how it does it.
On a real TN-C-S (Terre-Neutral-Combined-Separate) or PME (Protective multiple earthings) system widely used in the UK the Earth wire or the CPC (The Circuit protective conductor) is connected to the incoming neutral at the meter. This causes very high current which either blows the fuse in the plug or trips the circuit breaker making it safe. There is another commonly used system in the UK: TT (Terre-Terre) in which the CPC goes only to an earth rod. This does not trip the breaker as the current is not high enough. Therefore on TT RCD protection is absolutely necessary (not just required additional protection). Typically one has two levels of RCD protection 100 mA for the earthing to work and 30 mA for additional protection - though I think one could have only the latter (not sure). Three is also a third method known as TN-S (Terre-Neutral-Separate). In it there re separate earth and neutral all the way from the socket. It is not used anymore on new installations as it requires more wire. It works just like TN-C-S in case of a fault, it just uses the separate earth wire. There are also other systems but they are not used in the UK - at least on residential use.
I should say that I was not confused by the video, which was excellent! I hope I am sufficiently skilled to build this in a couple of days. One last question, what were the scissors for?
Current takes all paths. The element has actually lower resistance. A 3 kW kettle has just 19.2 ohms. However, while the kettle uses 13 A, only 0.1 A can kill. Also the wire can get completely loose so that it does not connect to the heating element.
The earth wire does not go to the earth on a TN system. It goes to the transformer via a copper connection. On a TT system it goes to the earth but then the resistance is so high that it does not blow the fuse. On TT one must have an RCD to make it safe.
One should abandon the term "earth wire" and use the proper term the CPC (The circuit protective conductor). That tells what it does without giving false implications how it does it.
I'm a bit confused about how the fuse blows up.
please explain
The fuse blew because the current (amps) exceeded the fuses 13amp rating.
@@uncontrollable343 Actually it takes some 21-23 A to blow a 13 A fuse.
On a real TN-C-S (Terre-Neutral-Combined-Separate) or PME (Protective multiple earthings) system widely used in the UK the Earth wire or the CPC (The Circuit protective conductor) is connected to the incoming neutral at the meter. This causes very high current which either blows the fuse in the plug or trips the circuit breaker making it safe.
There is another commonly used system in the UK: TT (Terre-Terre) in which the CPC goes only to an earth rod. This does not trip the breaker as the current is not high enough. Therefore on TT RCD protection is absolutely necessary (not just required additional protection). Typically one has two levels of RCD protection 100 mA for the earthing to work and 30 mA for additional protection - though I think one could have only the latter (not sure).
Three is also a third method known as TN-S (Terre-Neutral-Separate). In it there re separate earth and neutral all the way from the socket. It is not used anymore on new installations as it requires more wire. It works just like TN-C-S in case of a fault, it just uses the separate earth wire. There are also other systems but they are not used in the UK - at least on residential use.
@@okaro6595 if you want be accurate you’d say 1.66x times the rating. But that wasn’t the question asked was it.
@@okaro6595 very rare you’ll find a TT system on a residential property. The majority is TNS. Definitely not “common” at all.
Guess what I'm building over half term!
I'm confused by the video title... Was it meant to say "Fuses prevent electric shocks? Wrong!"?
You’re right! Changed now, thank you.
I should say that I was not confused by the video, which was excellent! I hope I am sufficiently skilled to build this in a couple of days. One last question, what were the scissors for?