The electrical outlet and power plug type I are widely used in Australia, Argentina, China, Papua New Guinea, and New Zealand.
The plug, which is rated 10 amps, has two flat pins, 1.6 mm thick.
The pins are set at 30° to the vertical, making them form an inverted V. The pins are 17.3 mm long and 6.3 mm wide. The center of the two flat pins is 13.7 mm apart.
Aside from the two flat pins inclined at 30° to the vertical, there is a flat earthed pin, 1.6 mm thick, 6.3 mm wide, and 20 mm long. There is a distance of 10.3 mm between the flat earthed pin and the middle of the plug.
There is an ungrounded version of the plug, which features two flat pins inclined to form an inverted V. The ungrounded version of the plug, has insulations, which prevents electrocution when plugged halfway.
There is also a 15 amps grounded version of the plug, which bears all similarities to the standard grounded type I plug, except that its grounded pin has a width of 8 mm.
The 10 amps standard type I plug will fit into the 15 amps socket, but the 15 amps plug can only fit into a special 15 amp socket.
The 15 amp plug/socket isn’t the only version available. There is also a 20 amp variant. So both the 10 and 15 amp plugs will fit into a 20 amp type I socket.
But the same can not be said about a 20 amp type I socket fitting into a 10 amp or 15 amp type I socket. This is because a low amperage plug typically fits into a high amperage socket.
There are slight differences in type I plugs used in various countries. For example, the Australian type I plug is known as the standard AS 3112.
China’s type I plug is 1 mm longer than the standard length of the plug. In addition, China’s type I sockets are installed so that the earth’s contact faces upwards.
The Australian variant bears similarity in dimensions to the type A plug. Therefore, when the history of the Australian variant is considered, it becomes unsurprising.
The Australian type is an outdated version of the American variant.
In 1916, the electrical engineer Harvey Hubbell II, who manufactured the type A plugs, patented what is now known as the Australian type I plug.
The three-blade plug design did not get much attention in the US since it was incompatible with the type A plugs in circulation in the US.
Australia preferred the plug over the British type D plug because it was easier for local manufacturers to produce flat pin plugs instead of round pin plugs.
That preference in Australia prompted the State Electricity Commission of Victoria, and the Australian electrical accessory manufacturers, to make the plug Harvey Hubbell II plug the standard plug in the country in the 1930s.