Appliances are pieces of device designed to carry out and achieve a specific purpose. They may appear big or small in size but all appliances have their designated task that will generate desired results in Kitchen Appliance Packages. Electrical Appliances are devices that operate effectively with the use of electricity. Electricity is an energy that is conducted through the interaction of electrons.
Electrical Appliances can be categorized into two major classes, namely, class 1 and class 2. Although, there are other classes of electrical appliances which depend largely on their level of protection and they are class 3, class 0 and class 01 but class 1 and 2 appliances are more important than the other three classes.
While carrying out Portable Appliance Testing (PAT), it is necessary to put into consideration, the class of appliances, that is, identifying the classes of appliances as the kind of test carried out on class 1 appliances is different from that carried out on class 2 appliances and that of class 2 is different from other classes of appliances.
A problem that usually occurs when carrying out Portable Appliance Testing (PAT) is the lack of knowledge to differentiate between a Class 1 appliance and a class 2 appliance because each class of appliances has different PAT approach. However, an easy way to differentiate between both classes of appliances usually lies in the symbols each of the classes carries. Where class 1 appliances do not usually have any symbol on them, class 2 appliances can be recognized with the symbol of a square enclosed or placed in a larger square as shown in the diagram below:
Asides using the symbols mentioned above to identify them, there are other ways of differentiating and identifying these classes of appliances, some of which has been discussed as follows:
Class 1 appliances have two protection levels which are the Basic Insulation and Earth Wire. The combination of the earth wire and insulation protects users from suffering from electric shock but if there happens to be a failure in the basic insulation, the user may suffer electric shock but provided the latter does not occur, the user is very safe to utilize the appliance. Also, an appliance whose plug has a fuse and a metal earth pin, possesses three (3) major cables (neutral, earth and live cable), made of metal etc. might fall into the category of a class 1 appliance.
However, when carrying out the Portable Appliance Testing on class 1 appliance, two tests are usually carried out, which are the “insulation resistance test” and the “earth continuity test” Class 2 appliances also have two level of protection. It possesses double layers of insulation which protect its users.
They are often regarded as “double insulated” appliances because of the two layers of insulation they have and they do not need the connection of an earth. Appliances with plastic case and plastic earth pin with a double square symbol are usually referred to as class 2 appliances, and the Portable Appliance Testing technique used to test such appliances is simply the “insulation resistance test”.
Examples of class 1 appliances may include an electric kettle, a metal lamp, a table fan etc. as they do not have any symbol on them and they all possess an earth point while examples of Class 2 appliances include Food Mixers,
Grinders, Drills and Hair Dryers among others.
To get top notch home electrical appliances as stated above visit allgreatappliances.com. it is important to know that class 2 appliances are safer than class 1 appliances because the former, irrespective of its wire installation state, always have its two levels of protection available for users safety unlike the latter which solely rely heavily on external wire installation and need to be inspected often to ensure that there is proper connection between the local earth potential and the main socket earth Below are brief explanations of other three classes of electrical appliances:
For the Class 3 appliances, the features built into class 1 and 2 appliances are not required as this class of appliance relies on a separate transformer which has a special safety feature known as the “SELV” which simply means “Safety Extra Low Voltage”. SELV has a very low Voltage and when users come in contact with it in normal conditions, will not result in any electric shock. Its symbol is a kite that has three vertical lines drawn directly in it as shown below:
Figure 2: Symbol of a class 3 appliance
The class 01 and class 0 appliances are appliances that have just one level of protection where class 0 has just a basic insulation designed to protect users from electric shock and class 01 has provision for Just a power supply cord that does not have any earth connection or conductor in it moreover, because of the default that the class 01 and class 02 appliances possess in them, which is just one level of protection, they are not allowed for sale in order to promote safety among users should complications arise in the long run. In a nutshell, if a PAT is done on an appliance and the default features of the class 0 and 01 appliances are detected in such appliance, the appliance will not be allowed to be sold to the general public. However, the class 01 appliances are sometimes used by some specialists but they are not used on a daily basis