Archive for the ‘Safety’ Category

Electrical safety

Another domain where different cultures have a very different approach is electrical safety. Each time I travel to the US, in particular with my kids, I feel somewhat unsafe when I look at the electrical equipment there compared to what is routinely found in Europe.

Plugs and outlets

European plug

It starts with the plugs and outlets. In any modern installation in France, it is extremely difficult for a child to touch a live piece of metal by manipulating a plug or probing an outlet. Here are a few of the safety features:

  • Large plugs (live, neutral and ground) have a round shape that fits precisely in the circular bezel on the socket. The depth of the bezel matches the length of the prongs, so that you cannot touch them when they are live.
  • Smaller two-wire plugs (live, neutral only) have plastic covering the base of the prongs, so that the metal does not touch a live part until only plastic is accessible outside the socket.
  • In the socket itself, at least for sockets installed in the past 5 years or so, there is also a small plastic cover, which gives way only if both sides are pushed at the same time. This prevents little kits from pushing metallic objects in the socket.
  • The plug and socket hold together pretty well, it takes an effort to remove the plug.

By contrast, the US electric plug seems designed to hurt. It is small, often leaving the socket all by itself (under its own weight), shows live metal, and a kid’s finger can easily touch both at the same time.

Circuit protection

There are also much less stringent norms in the US regarding circuit breakers or electrical safety, as far as I can tell. Safety is apparently considered more a matter of education.

In France (probably in the rest of Europe as well), it is mandatory to have a number of ground fault circuit interrupter (GFCI) in any home. While regulations have changed over time, the current standard requires a 500mA differential protection for the home, and 30mA differential protection for practically all circuits leading to an electrical outlet. The 30mA differential protection means that if you touch a live wire and the ground at the same time, enough current will flow through the ground that the circuit breaker will trigger. In theory, 30mA is considered less than what can stop your heart. In practice, it means that you usually don’t even feel the electric shock, the only punishment being that you find yourself in the dark.

In the US, GFCI are now mandatory for electrical outlets in the bathroom since 1975 and the kitchen since 1987. I have not found any norm on acceptable leakage currents, but I suspect they are also in the milliampere range. But the GFCI is generally found on the socket itself, which has a number of drawbacks. A minor drawback is that it exposes the mechanism to dust, unintentional activation, shocks, and other wear and tear, compared to a circuit breaker placed in a fuse box. The second, which I find more serious, is that it offers no protection against a loose socket, something which I have found to be frequent in wood-based construction like in California. Finally, it’s more expensive, since one GFCI protects one socket at most (or twin sockets).

In any event, despite code, a large fraction of the homes I have visited in the US still don’t have GFCIs on the majority of sockets, meaning that any small kid still has easy access to electricity all over the house, notably in the bedroom.

The People Mover

This approach to electrical safety is not unique. It reminds me of my first visit to Detroit, and my amazement at seeing the People Mover. Why was I amazed? Because my father had told us a lot about the D line of the Lyon subway (which kept him busy for a few years), and claimed that this was the first fully automated subway in the world which was smart enough to not require doors in the stations (to prevent folks from jumping on the tracks). And here I was, the People Mover was fully automated, had no automatic doors in the stations, and looked a bit older than the D-line hardware.

But then, I did not see the subtle infrared detectors and other tricks that the D line subway uses to prevent the loss of life. So I asked my host: “What if someone jumps on the tracks” The answer was terse: “well, he would die“. Simple. Culturally different.

Categories: Safety, Sociology

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