Thai TIS 166 – Thailand

Our Siamese power cables and Type O plugs, using the quality Longwell LP-81, like all our products, are backed by the Morvan Trading guarantee of the best technical knowledge available, and customer service that always goes the extra mile to make the mains cable selecting and purchasing experience as smooth and seamless as possible. 

Contact our sales team for competitive pricing, or for any technical or quality approval information, and receive a rapid comprehensive response by return.

Contact our friendly technical team for more information call us on 01264 353489 or click here to contact us

Whilst similar in appearance to the Israeli plug and a now obsolete Greek plug, it is not compatible: the new Thai plug is only used in Thailand.  However, the same Siamese style hybrid Thai socket is used in surrounding countries including Laos, Cambodia and Vietnam.

Contact our friendly technical team for more information call us on 01264 353489 or click here to contact us

Thai TIS 166 – Thailand standard

Historically, Siam used both North American and European-style plugs, as imported equipment would normally come with either of the two types.

Thailand sockets originally only accepted one type or the other, but hybrid sockets were then designed that accepted both patterns. The live and neutral apertures are flat on one side and rounded on the other, to accept flat USA and round Euro pins. Sockets may be switched, but this is not currently a requirement.

A third aperture provides a grounding connection for the earth pin of the USA plug; no earthing is provided for European Schuko-type plugs.

Thailand operates at 220V 50Hz, which is acceptable for the European style plugs, but the North American style plugs (and the equipment they power) were designed to operate at 110V 60Hz which willbe an issue for anything that cannot regulate its own voltage.

The plug and socket were originally described in Thai Industrial Standard TIS 166:2547, but the plug has been revised and updated to TIS166-2549. These were issued by the Thai Industrial Standards Institute or TISI. Dates for Thailand are given in the Buddhist Era, and 2549 equates to 2006 in the Gregorian calendar. TIS 166:2547 also includes a provision for a solely round pin socket, to eventually phase out the 2 pin and 3 pin flat blade USA plugs in preference for the new style.

Contact our friendly technical team for more information call us on 01264 353489 or click here to contact us

To remedy this potentially unsafe disparity in voltages and lack of earthing, the Thai government decided to introduce a new style plug. The TIS166 was essentially reverse-engineered to fit the hybrid sockets, so has the live and neutral pins of a European plug (4.8mm diameter, 19mm long, 19mm apart, partially insulated) with the earth pin of a USA plug (4.8mm diameter, 21.4mm long, offset by 11.9mm).

This ensures an earth connection and removes the voltage issue. As well as an improvement in electrical safety, the introduction has also been seen as a protectionist measure to aid the Thai manufacturing economy by reducing its reliance on imported mains cables and related other products.

Thai plugs were not originally one of the product categories that required mandatory approval. However, this changed in January 2021, and after a 6 month grace period, all imports and sales of Thai plugs and power cables now require TISI approval.

The voluntary TISI mark was the TISI logo; now it is mandatory, it has a circle around it.The TISI safety mark must be on the face of the plug, and additionally on the packaging. Sizing of the mark must be suitable and proportional, and not less than 3mm. The standard number must be included, at not less than 1.5mm. A QR code of not less than 10mm also allows end users to check this. As we or our customers may resell these in less than box quantity, or even singly, we have taken the measure to fulfil the packaging requirements by means of a label attached to each individual power cable.

Contact our friendly technical team for more information on TISI plugs: call us on 01264 353489 or click here to contact us