Travel Adaptors and PAT Testing

32A circuit breaker protecting a ring circuit

Why British plugs contain a fuse

Travel adaptors allow electrical equipment fitted with a foreign plug to be connected to a UK socket. However, they must be correctly designed to provide protection equivalent to a standard BS 1363 plug.

Socket outlets in the UK are typically supplied by a ring circuit protected by a 32A circuit breaker. This differs from many other countries, where socket circuits are radial and protected by lower-rated circuit breakers.

The fuse fitted inside a BS 1363 plug protects the flexible cord connected to the appliance. Most appliance flexes are rated at 5A or 13A, far below the 32A rating of the circuit breaker. Without a fuse, a fault could allow excessive current to flow through the flex, causing overheating and potentially leading to fire.

Most foreign plugs do not contain a fuse, so when such equipment is used in the UK it must be connected via a properly fused adaptor or conversion plug to provide equivalent protection.

Legal requirements for travel adaptors

Adaptors designed to allow foreign plugs to be used with UK sockets must comply with the Plugs and Sockets etc. (Safety) Regulations 1994 and BS 1363.

A compliant adaptor must:

Be fitted with a correctly rated fuse
Have shutters protecting the live and neutral contacts
Be approved by a recognised certification body (such as BSI or ASTA)

Travel adaptors are intended for temporary use, for example by visitors. They are not suitable for permanent installations or long-term workplace use. Where equipment is used regularly, the correct solution is to fit a BS 1363 plug or an approved conversion plug.

adaptor with shutters — **Fig.1.** L & N contacts must have shutters

adaptor with fuse — **Fig.2** Adaptors must have a fuse fitted

Substandard adaptors

Substandard travel adaptors that do not meet UK safety requirements are commonly encountered during inspection and PAT testing. These adaptors may lack a fuse, have no shutters, or be incorrectly constructed. Such defects significantly increase the risk of electric shock or fire.

un-fused adaptor — **Fig.3** Un-fused adaptor, no approval mark

adaptor missing shutters — **Fig.4** No shutters on the L & N contacts

adaptor allows earth pin to be connected to live — **Fig.5** Earth pin can be plugged into the live terminal!

Fig.5 & 6. Demonstrate how a non-compliant plug adaptor will allow the earth pin of a BS1363 plug to be plugged into the live terminal. This is extremely dangerous, the metal case of a Class I appliance in this situation would become live.

adaptor with CE mark — **Fig.7** Un-fused adaptor, CE marked

adaptor with no shutters — **Fig.8** No shutters on the L & N contacts

Fig.7 shows an adaptor incorrectly marked with CE. Plugs and socket adaptors covered by BS 1363 are not subject to CE or UKCA marking, as they fall under the Plugs and Sockets etc. (Safety) Regulations rather than the Low Voltage Directive.

"CE marking is not to be used. Its use may constitute an offence under section 1 of the Trade Descriptions Act 1968." - Guidance notes on the Plugs and Sockets etc. (Safety) Regulations 1994.

Identifying substandard or counterfeit accessories is an important part of inspection. See examples of counterfeit electrical equipment found during PAT testing. The visual inspection is the most effective way to identify dangerous or non-compliant accessories before testing takes place. This is a key area covered on our PAT testing courses, where delegates learn how to recognise unsafe plugs, adaptors and counterfeit electrical equipment.

Conversion plugs and new equipment

Electrical equipment supplied for use in the UK must be fitted with a BS 1363 plug or an approved conversion plug. Travel adaptors must not be used as a permanent solution.

Conversion plugs are designed to fully enclose the original plug and must be fitted using a tool so that they cannot be easily removed. They must also contain a fuse and carry approval markings. This ensures the equipment remains compliant with UK safety regulations.

BSI approval mark — **Fig.10** Must be fused, approved and screwed shut.

The supply of electrical goods in the UK is covered by statutory legislation under the Plugs and Sockets etc. (Safety) Regulations 1994. Further information:equipment-plugs-sockets-guidance-notes.pdf

PAT testing and travel adaptors

Travel adaptors should always be carefully checked during PAT testing. Adaptors that are unfused, damaged, incorrectly marked or poorly constructed should be removed from service immediately.

For further information on managing electrical safety and inspection programmes in the workplace, including the identification and removal of unsafe equipment, see our article on managing PAT testing in the workplace.