Monday, September 21, 2020

2-pin or 3-pin plug? This is a problem

Some may think all Singapore electric home appliances must use 3-pin plug. Which is not the case. 

Basically, there are 3 types of legal plugs allowed to be used in Singapore. Refer to below image. Download the document for more details.

Legal Plugs in Singapore
 
It is not compulsory for an home appliances to use the 3-pin plug, even it bears a safety mark. BTW, not all appliances require a safety mark. Only controlled goods are required. We will elaborate on this matter in another post. 
 
Only in two cases, 3-pin plug must be used. (1) required by law. (2) the wattage of an appliance exceeds 500W. Let us explain the second case in details. 
 
Pay attention to the 2-pin round plug. It has a prefix "2.5 AMP". This indicates the maximum current allowed to flow through the wire. Apply the formulae: P = UI = 220 x 2.5 = 550W. In other words, the maximum wattage of an appliance which uses 2-pin plug is roughly 500 W.
 
Finally, a separate safety mark is required for the 3-pin plug. So an appliance should bear two safety marks, if it uses 3-pin plug. One for the appliance itself, another for the plug.