Understanding European plugs and sockets

German (also known as type F, CEE 7/3 (socket), CEE 7/4 (plug), Schuko

Most commonly known as ‘Schuko’ connectors (Schutzkontakt is German for ‘Protective contact’), the design originated in Germany. The plug is rated at 230v 16A, and has two 4.8mm x 19mm pins. The earth connection is made by two earthing clips on the sides of the socket, which engage with the earth strips on the side of the plug (there is no earth hole).

The connector is un-polarised, meaning that it can be inserted either way around, allowing the live and neutral to be reversed. There is no convention as to whether sockets have the live wired to the left or right hole.

French (also known as type E, CEE 7/5 (socket), CEE 7/6 (plug)


Originally developed in France, the plug is rated at 230v 16A, and has two 4.8mm x 19mm pins. The earth connection is made by an earth pin which protrudes from the socket, and engages with a hole in the plug (there are no side earth strips). Until 2002, there was no convention as to whether sockets had the live wired to the left or right hole. However, it is now more likely that the live will be wired to the right hole (as you face the socket). This cannot be relied upon, as many sockets are still wired the other way, and to further confuse matters, the Czech standard still recommends wiring the live to the left hole! Due to the earth pin projecting from the socket, the plug is polarised, so can only be inserted one way around.


Universal CEE 7/7 Plug

In order to bridge the differences between German and French standards, the CEE 7/7 plug was developed. It has a hole to accept the earth pin on a French socket, and side strips to connect to the earth clips on the side of German sockets. It is often incorrectly referred to as as Schuko plug.

Safely Using Sockets Abroad

Why is an earth connection so important?

Many appliances require an earth connection to operate safely. An earth connection ensures that if there is a fault and an external metal part becomes live, the earth wire safely conducts the electricity away, tripping the circuit breaker or blowing the fuse. For example, imagine charging an electric car. If an earth connection is present, then if there were to be a fault and the metal body of the car became live, electricity would flow down the earth wire, quickly cutting off the power. If there was no earth connection, the car would remain live. If you were to touch it, electricity would flow through your body to the ground, with potentially fatal consequences.

You must always ensure that the adaptor you use connects the earth pin. It is therefore best to use adaptors with a universal plug connection (an earth hole and metal side strips), as they will work with both French and German types of socket. It is possible to insert a French plug into a German socket, and for a German plug to fit into a French socket- the appliance will work, but there will be no earth connection.

You must also never assume that just because a socket has an earth connection, that it is actually wired to earth. The only way to find out is to use a socket tester (see polarity section).

Some appliances do not require an earth connection. They are known as type 2 and will have a symbol of a square inside a slightly larger square on the appliance label. Other clues (although not 100% reliable), are a plastic case or flat 2 core cable.

Why should I worry about polarity?

The UK electrical system is polarised. The earth pin on 13A plugs is at the top, they can only be inserted one way and the live is always wired to the right hole (as you face a socket). As the live is always connected one way, appliances are wired with this in mind. For example, a switch may only turn on/off the live wire. If the appliance is used in Europe and the polarity is reversed (e.g. the live is connected to neutral, and neutral to live) such as would occur when using a Schuko socket which can be inserted either way round, the switch now only turns on/off the neutral. The appliance would appear off, but it is actually still live.

This is particularly important when connecting caravans, motor homes or boats as they will often have circuit breakers that isolate only the live. If the polarity is reversed and a fault occurs, they will cut off the neutral. This leaves the faulty appliance still live, which could prove fatal, particularly if there was also an earth fault e.g. the metal of a caravan would remain live and electrocute anyone who touched it.

It’s best to use a lead or adaptor with a universal plug connection, as they will work with both French and German types of socket. Always use a socket tester to check the socket before connecting it. If the polarity is shown as reversed, there are the following solutions:

German socket: Simply pull out the plug, turn it 180 degrees, and insert it again.

French socket: Due to the protruding earth pin, the plug cannot be turned around. The only answer is to use our universal plug to German socket adaptor lead, which will enable the appliances plug to be inserted the other way around.

16A industrial socket: Use a polarity reversal adaptor, which is specially wired to reverse the live and neutral connection.

Can travel adaptors be dangerous?

Many travel adaptors are only suitable for low current applications such as charging phones. Our adaptor leads are made to enable high power UK appliances to draw a full 13 amps. Many adaptors also often dangerously do not connect the earth pin.