2002-06-01 Japan is split. Half uses 100 V @ 60 Hz and the other half uses 200 V @ 50 Hz. I'd suspect that Japan was all 200 V @ 50 Hz before the war, but when they rebuilt the damaged areas, it was done with American equipment using 100 V.
John ----- Original Message ----- From: "Bill Potts" <[EMAIL PROTECTED]> To: "U.S. Metric Association" <[EMAIL PROTECTED]> Sent: Friday, 2002-05-31 23:18 Subject: [USMA:20297] Re: North korea > This response is for Wizard. > > Most of Japan uses 100 V, so North and South America are not unique in their > choice of a relatively low voltage. Japanese plugs are the same as the U.S. > and Canadian ones. The kinds of appliances people take with them (e.g., > hairdryers, laptop computers) when they travel work fine in Japan and > (obviously) don't require special plug adapters. Most portable U.S. > appliances can also work on 240 V, 50 Hz (e.g., hairdryers on low setting > only). > > On the grounding issue, you should note that we have both 2- and 3-pin > plugs. The two-pin plugs tend to be on small appliances, such as hairdryers, > standard lamps, etc. > > On the 3-pin plug, the center, cylindrical pin provides true grounding. The > other pins are flat. > > With 2-pin plugs, the one that connects to the neutral side of the supply is > wider than the other (matching the socket). The plug cannot be inserted the > wrong way. The same is true for a 3-pin plug with the grounding pin snapped > off. > > Most plugs, today, are of the molded type (i.e., integral with the cord), > are very safe, and are very inexpensive. > > Appliances are not sold in the U.S. or Canada without plugs. Until fairly > recently, British consumers used to have to buy the plug separately and > install it on the end of the power cord. Inadvertent exchanging of the > neutral and live connections was not unusual. Even with the grounding pin, > that could lead to a dangerous situation. > > Power to U.S. and Canadian houses is 3-wire. Two are live and provide > full-wave 220 V AC for ovens, stoves, driers, etc. The third wire is > neutral. Half the house's 110 V circuits use one live, plus neutral. The > other half use the other live, plus neutral. The fact that the two sets of > half-wave circuits are mutually 180 degrees out of phase isn't a problem. > > The cylindrical ground sockets are not connected to the electrical system at > all, but to true ground (typically to metal brackets on nearby copper water > pipes -- or galvanized iron pipes in older houses). > > Bill Potts, CMS > Roseville, CA > http://metric1.org [SI Navigator] > > > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of > [EMAIL PROTECTED] > Sent: Friday, May 31, 2002 19:48 > To: U.S. Metric Association > Subject: [USMA:20296] Re: North korea > > > In a message dated 2002-05-31 20:16:18 Eastern Daylight Time, [EMAIL PROTECTED] > writes: > > > > > this shows who has the best tecnical solution! > > us plugs don't have grounding, do they? > > > Many do except for small items like lamps, clocks, etc. > > 240v allows for smaller wires (double voltage = half amperage, usually) but > it's more dangerous. > > 120v is the standard in all of North and South America, not just the USA. I > think also in a few other countries. > > Carleton > >
