Type O Socket And Plug

The Type O plug (TIS 166-2549 standard) is used only in Thailand and is one of Thailand's standard power plugs. It is rated for 16 amperes and has three round pins arranged in a triangular pattern, all with a diameter of 4.8 mm. The grounding pin in the center is 21.4 mm long, while the neutral and live pins are 19 mm long with their centers spaced 19 mm apart, and have a 10 mm insulated section at the base.

The pin arrangement and spacing of the Type O plug are identical to those of the Type B plug, because Thailand's universal sockets were designed to accommodate Type A, B, C, and O plugs simultaneously. According to Thailand's long-term plan, Thai sockets will eventually no longer be compatible with American Type A and B plugs, as Thailand's standard voltage is 230 V, which differs from the United States' 120 V.

However, there are currently no dedicated Type O sockets in Thailand. Type O sockets only exist on paper. All sockets sold on the Thai market are universal and can accommodate Type A, B, C, and O plugs simultaneously.

Although the Type O plug is somewhat similar to the Israeli Type H plug and the Danish Type K plug, they are not interchangeable. However, Type O sockets can accommodate Type E/F hybrid plugs without grounding, but using appliances without grounding may pose a risk of electric shock. Therefore, the Thai government banned the sale of appliances with Type E/F hybrid plugs in 2008. Since many Thai households still have previously purchased appliances with Type E/F hybrid plugs, a special adapter plug was developed. It allows Type E/F hybrid plugs to retain their grounding function when inserted into Type O sockets.