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Mounting cables in domestic homes in europe is works as such, that you have often -NYM cables. That is usually three wires wrapped in a double mantle. Nicely protected to be used inside or outside. Often carried along Walls/Bars or in dry walls or in cable holders. Actually a quite feasable and practical cable type. Using sockets with spring connection - just push the uninsolated ends in. enter image description here

Why would the US not use this type but instead have a more dangerous type? I am talking about typically yellow mantles with 3 wires. The wires have slightly less diameter, the earth is not insulated and the outer wrapping is thinner. Is it worth the money?

You know: less voltage -> higher current -> higher risk of fire.

But then those Wires are piped through a metal hose (preventing fire, I guess). Don't tell me this is cheaper than taking better diameter and insulation in the first place

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closed as primarily opinion-based by Chris Stratton, PeterJ, Dave Tweed Apr 28 at 0:48

Many good questions generate some degree of opinion based on expert experience, but answers to this question will tend to be almost entirely based on opinions, rather than facts, references, or specific expertise. If this question can be reworded to fit the rules in the help center, please edit the question.

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    \$\begingroup\$ "Feather" would be "spring" in english. \$\endgroup\$ – JRE Feb 28 '17 at 12:09
  • \$\begingroup\$ "You know: less voltage -> higher current -> higher risk of fire." You should probably have left that out of your question, because it's irrelevant and arguably wrong anyway. It isn't the intact wire that starts fires, it's the leakage paths in a damaged wire. Higher voltage will push more current through a given leakage resistance, resulting in higher power dissipation, not less. \$\endgroup\$ – Dave Tweed Feb 28 '17 at 12:42
  • \$\begingroup\$ @DaveTweed, not quite right there... N.A. cables have to carry double the current as the norm. That means they can handle LESS damage and create more heat generally. ELectrical fires in Europe are pretty rare compared to here. Fires are usually caused by damage, over-loading , or bad twist connections.. not leakage. \$\endgroup\$ – Trevor_G Feb 28 '17 at 13:53
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    \$\begingroup\$ @Trevor: Where are you getting your information? Sure, a 100W bulb requires half the current at 220V, compared to 110V. All that means is that in Europe, they put more loads on a given circuit, and the wires in the walls are carrying roughly the same amount of current in either case. Why would they waste money by using twice as much copper as necessary? \$\endgroup\$ – Dave Tweed Feb 28 '17 at 14:03
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    \$\begingroup\$ @Trevor. Yes and therefore a better insulation (eg. padding of the cable as a whole) makes an impact. To fire cause. \$\endgroup\$ – Robetto Feb 28 '17 at 14:26
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As far as I can tell it is mostly just that each country invented their own standards and has convinced themselves that their way is the "one true way" of doing things. Europe has tried to harmonise internally due to the EU/EEC with some but limited success.

It is difficult to make unbiased comparisions, you could say that an insulated earth is better because it reduces the risk of shorts to earth or you could say that an uninsulated earth is better because if the cable is going to fail you would rather it failed with a short to earth which will quickly trip a breaker than fail with some more insiduous failure mode. Which opinion makes more sense depends heavilly on how much you trust your earthing system.

Similar arguments can be made for voltage, the higher voltage system has a lower risk of fire, the lower voltage system has a lower risk from electric shock.

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    \$\begingroup\$ Wrong on the lower risk of shock part, there is a lower risk of death from shock... but the North American electrical plugs and outlets are horrendously dangerous compared to other countries. No interlocks, no trap-doors to close the outlets, no fused plugs, no on outlet switches.... Risk of shock is actually MUCH higher in N.A. \$\endgroup\$ – Trevor_G Feb 28 '17 at 13:48
  • \$\begingroup\$ Europe has a mess of plug and socket types that lead to some very safe combinations but also some not very safe ones such as earthed plugs that will fit in unearthed sockets or even worse earthed plugs that will fit in earthed sockets but neverthless fail to provide earth continuity. \$\endgroup\$ – Peter Green Feb 28 '17 at 15:02
  • \$\begingroup\$ Ya @PeterGreen, I guess I am more thinking of the UK. \$\endgroup\$ – Trevor_G Feb 28 '17 at 15:12
  • \$\begingroup\$ Trevor...Europeans use outlets w/moving parts cuz the high voltage they use is super dangerous. 115V across the chest on dry skin will scare the @#$% out of you. 240 across the chest on dry skin will cause fatal heart fibrilation. \$\endgroup\$ – Robert Endl Feb 28 '17 at 18:37
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The USA National Electric Code (NEC) describes where the type of wire described can be used. It is not permitted to be used without additional protection in several of the places that NYM is used. The other types of wire and additional protection used in those places in the USA mean that the wiring is better protected that NYM. The wire size vs current needs to be considered along with insulation temperatures rating, permitted ambient temperature vs. wire size and branch circuit protection requirements. All things considered, I think it is difficult to argue that the European wire insulation system system is superior to the USA system.

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You seem to have a few misconceptions about North American wiring practice and standards.

The wires [in North American NM cable] have slightly less diameter, the earth is not insulated and the outer wrapping is thinner. Is it worth the money?

There isn't one fixed size for the wires in this cable.

NM cable (commonly called "Romex", a dominant brand name) is available in a variety of wire diameters. AWG 14 (2.01 mm2) is commonly used for 15 A circuits, and AWG 12 (3.31 mm2) is commonly used for 20 A circuits. Larger diameters are available up to at least AWG 2 (33.6 mm2).

You know: less voltage -> higher current -> higher risk of fire.

Higher current also requires larger wire diameters to reduce voltage drop, requiring more copper.

But this is a separate issue from the type of cable used. It's been debated to death in the past. And the installed infrastructure in N.A. would be immensely expensive to change to increase distribution voltage.

But then those Wires are piped through a metal hose (preventing fire, I guess).

NM cable is typically not carried in conduit, though it may be.

Conduit is required where the wire would otherwise be accessible (on a wall surface, for example), not when the cable is in a wall cavity. AFAIK the main function of the conduit is to prevent mechanical damage, not fires.

When conduit is used, NM cable isn't required --- individual wires can simply be pulled through the conduit.

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Because the north American electrical standards are as old as Edison... and have never really been updated like they were in the UK and Europe.

We still use basically glorified twist-ties to join wires together.

enter image description here

Those always scare me to death...

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    \$\begingroup\$ The question is about the use of a specific wire type, not electrical standards in general. This answer makes no effort to address the question asked. (-1) \$\endgroup\$ – Charles Cowie Feb 28 '17 at 14:24
  • \$\begingroup\$ Really.. @CharlesCowie, the answer IS because the whole system is old and seriously needs revised. Agreed, the image is not strictly related to the question, but it serves to highlight that the system as a whole is seriously outdated. If you can think of a more specific reason please add your own information. \$\endgroup\$ – Trevor_G Feb 28 '17 at 14:27
  • \$\begingroup\$ I agree that the outlet guarding problem mentioned in your comment is a good point. I think the biggest problem with the twist connectors is improper use. However commentary and answers that tend to expand the scope of the question this way is not really the way this forum is supposed to operate. \$\endgroup\$ – Charles Cowie Feb 28 '17 at 14:43
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    \$\begingroup\$ Crimped splices, afaik. \$\endgroup\$ – The Photon Feb 28 '17 at 16:44
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    \$\begingroup\$ Proper wire nuts tend to be the most reliable electrical connection available for commercial and residential electrical system branch circuits. As an electrician apprentice, we used to use crimp splices (T&B Stak-Kon splices) for joining 2-5 #14 wires. However, the solid copper conductors "cold-flow" over a period of years, leading to resistive connections. My master (Electrician) had us switch to Murrette / Marrette wire nuts and I am NOT aware of any failures WHEN those are installed properly. Problem is that most lay people don't know how to install them properly. \$\endgroup\$ – Dwayne Reid Feb 28 '17 at 17:28

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