Difference between 2 pole and 3 pole Adapters HD

What does 2-pole mean?

2-pole means that the device plug is not earthed and that it normally has two pins which transmit electricity.

Originally, all electrical devices were fitted with 2-pole plugs, which mean that the devices were not earthed and that all mains sockets were constructed for 2-pole plugs. With the predominance of more and more powerful devices, the risk of an electric shock increased. This problem was solved with the installation of an earth connection (mostly in the form of a 3rd pin). This is why earthed plug systems are known as 3-pole systems although this is not quite technically correct.

In the case of less powerful devices (normally up to around 500 watts), 2-pole connections are still the norm since these can be produced more cheaply.

In most countries in the world, the 2-pole mains sockets have been replaced with earthed sockets which can accept both 2-pole and 3-pole plugs.

What does 3-pole mean?

3-pole means that the device plug is earthed and that it normally has three pins, of which two are used to transfer the current and one is used as personal protection.

Due to the predominance of more powerful devices in the 1930s (normally above around 500 watts) the problem of a possible electric shock became a hazard for the user. In order to provide safety, an earth connection had to be fitted to the 2-pole plugs for these devices. In all plug types, the earth connection was fitted as a 3rd pin.