To add a bit to Rich's comment.
The Argentina and China (PRC) plugs have polarized plugs that are very similar to Australian style (without a caliper it is hard to tell the dimensonal differences). The PRC plugs are the same as the Australian polarization while the Argentina plugs are opposite of the Australian polarity. The polarity of these plugs may be marked on the plug face (Argentina is by requirement). Also, the Swiss and Israel 3-conductor plugs are configured so that polarization is possible but I have not confirmed whether this is done within the facility wiring. The Israel sample that I have has the polarity marked on the plug face but the Swiss one is not marked. Oscar Rich Nute <[email protected]>@majordomo.ieee.org on 02/20/2002 12:38:19 PM Please respond to Rich Nute <[email protected]> Sent by: [email protected] To: [email protected] cc: [email protected] (Product Safety Technical Committee) Subject: Re: South Korean Power System Hi Ed: With few exceptions, most power distribution systems have one pole of the supply, the neutral, grounded. (Indeed, the definition of "neutral" for single-phase systems is the grounded conductor.) In the IEC scheme of the world, a power distribution system where the neutral is grounded is known as a TN or TT system. The first letter identifies the grounding scheme for the neutral wire. The second letter identifies the grounding scheme for the protective wire. T = terra (a ground rod) N = neutral In North America, the scheme is TN. The neutral is connected to a ground rod at the service entrance. The protective wire is connected to the neutral in the breaker panel. I believe Korea uses the TN system. So, at any socket-outlet, one pin will be at the phase voltage, 220, and the other pin will be at the neutral voltage, 0. Polarity is a separate issue. By polarity, I mean that the neutral identification is maintained through the plug/socket-outlet scheme. Polarity is not maintained where the plug can be reversed in the socket-outlet. The SCHUKO plug is a plug that can be reversed in the socket outlet. Not only that, but the socket-outlet is symmetrical, so the wiring to the socket-outlet cannot be such that the neutral is always wired to the same pin. Among the world's plugs/socket-outlet combinations, relatively few maintain the polarity through the system. These are: the British 13-A plug/socket-outlet in UK, Ireland, Hong Kong, Singapore, etc. the old British 15-A plug/socket outlet in South Africa and India, etc. the Australian plug/socket-outlet the North American grounding plug/socket-outlet the North American two-wire plug/socket-outlet with one wide blade The French plug/socket-outlet with its grounding pin scheme COULD be polarized, but is not so wired. Likewise, the Danish, Chilean, and Chinese plug/socket-outlet could be polarized, but I cannot say if they are. Polarized plugs and socket-outlets always bear markings indicating the pole of each pin. For North American plugs and socket- outlets, the white or silver-colored screws or terminals are the neutral pins. Other plugs and socket-outlets bear molded in letters such as L, N, E or PE or G. Virtually all safety standards include the requirement that the neutral wire within the equipment shall be treated as if it was at mains voltage rather than at zero voltage. This is because, in many installations, errors may occur in the wiring of the socket- outlet. Best regards, Rich ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: [email protected] Dave Heald: [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on "browse" and then "emc-pstc mailing list" ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: [email protected] Dave Heald: [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on "browse" and then "emc-pstc mailing list"
