Kena1921 wrote:
Could you expand on the following...
This sensation may be alleviated by turning the AC plu 180 degrees.
That is certainly true in the U.S. and other countries with 110VAC. I have two 110VAC lines coming from the power company. Each one is 110VAC relate to earth ground. They're phased 180 degrees apart and there is 220V between them. In my house, earth ground is obtained by a connection to the cold water pipe on the feed side of the meter. Also, a "Neutral" is created by a connection to ground. Although they are carried on separate physical wires, Ground and Neutral are electrically identical.
"Normal" appliances and receptacles utilize the 110VAC line and the Neutral line. The ground wire is carried as a safety mechanism in case the Neutral breaks. (Otherwise, the human might provide a path to ground, which is unpleasant, at best.) Heavy duty appliances (such as electrical clothes dryers) utilize both 110VAC lines and no Neutral and operate at 220VAC. The Ground is still present for safety.
SOME 110VAC devices have plugs that include a third prong for Ground. These plugs can not be reversed 180 degrees. SOME 110VAC devices have plugs that do not have the third prong but are mechanically polarized (one prong is wider than the other). These plugs also can not be reversed. The Apple charger does not have a Ground prong and does not have a polarized plug and therefore can be reversed.
Turning the plug 180 degrees changes which wire inside the charger is connected to Neutral and therefore to Ground and that frequently eliminates what we refer to as "60 cycle hum" (in the old days, Hz was known as cycles/second).
By the way, my reference to "110V/220V" is the result of common usage where I grew up. Others call it 115V/230V or even 120V/240V. The actual values could be anything in that range.
Now, can anyone educate me regarding the wiring Europe?