Originally Posted by SvenNYC
C-H it is ungrounded.

Korean wiring doesn't use grounds or neutrals.

It is 220 volts across hot & hot [Linked Image]


Resurrecting this ancient thread because it still seems to be popular on the web.

According to all sources I've found, the Republic of Korea (South) migrated from a US system (120/240 V, 60 Hz, NEMA plugs) to 230/400 V 60 Hz using Schuko sockets starting in the 1970s. I've seen pictures of services that clearly indicated three phases plus neutral, supporting the 230/400 V claims. Sockets are regular German Schuko but designed to cram a double into an American box.

Here's the only one I've ever seen for sale online with (sort of) English description:
https://www.ebayshopkorea.com/itm/2...Outlet-Panel-EU-220V-KOREAN/222470620152

North Korea apparently also uses Schuko sockets but the mains frequency seems to be 50 Hz.