One of the many exciting things about modern household appliances is why some of them come with 3 socket plug (ปลั๊ก 3 ตา , which is the term in Thai) and others with only 2. The difference between these two plugs is significant; understanding them is just a matter of knowing what to look for.
The reason that some plugs come with three pins is that they are “grounded.” This means that the third pin connects directly through a series of wires to the ground outside of the building. In case of an electrical problem, you don’t want the electricity seeking to ground inside your home, as this could cause a fire; it is safer to have it grounded outside.
Appliances that don’t use three pins don’t take a lot of electricity to require a grounding. Even in the worst case scenario, a problem with these electronics would only provide you with a mild shock.
Cutting the Third Pin
It is recommended that the third pin attached to the wire on an electrical plug. It is there for your safety. Although it can be a hassle to work around, it is much safer to leave it in place.
Where a neutral conductor is involved in supply wiring, the polarization of the plug can boost safety by preserving the distinction in the equipment. For instance, appliances may ensure that switches interrupt the line side of the circuit, or can connect the shell of a screw-base lamp-holder to neutral to avoid the risk of electric shock. In some forms, polarized plugs can’t be mated with non-polarized sockets. Wiring systems where both circuit conductors have significant potential concerning earth do not benefit from polarized plugs.
Universal or multi-standard sockets are designed to accommodate plugs of various types
A technical standard may include compatibility of an outlet with multiple forms of the plug.