Common Installation Mistakes for Plugs and Sockets
At present, flush-mounted sockets are generally used in home renovation. There are many types of sockets on the market, but they are largely similar in form. Homeowners are advised to choose branded sockets to ensure quality. The following points should be noted during socket installation:
1. Installation height. Where the design specifies a height, install according to the design. Where the design does not specify it, the following generally applies: sockets with safety shutters shall be not less than 0.3 m above the floor; sockets without safety shutters shall be not less than 1.8 m. It is advisable to buy sockets with safety shutters whenever possible, as the price difference is small.
2. In bathrooms and other damp areas, use well-sealed waterproof and splash-proof sockets.
3. The faceplate should be straight and sit flush against the wall. Wiring (polarity) shall meet the following requirements: for a single-phase two-hole socket, facing the socket, the right-hand or upper hole is connected to the live conductor (hot); the left-hand or lower hole is connected to the neutral conductor. For a single-phase three-hole socket, facing the socket, the right-hand hole is connected to the live conductor (L, hot), the left-hand hole to the neutral conductor (N), and the upper hole to the protective earth conductor (PE).
Five Common Mistakes in Socket Installation
1. Socket installed too low. Many homeowners install sockets in low, concealed positions because they think higher sockets look unsightly. This makes it easy for water to splash into the socket when mopping the floor, leading to electric shock. Industry practice: surface-mounted sockets should preferably be at least 1.8 m above the floor; flush-mounted sockets should be no less than 0.3 m above the floor. Sockets in kitchens and bathrooms should be at least 1.5 m above the floor, and air-conditioner sockets at least 2 m.
2. Only one circuit. Older homes often have only one circuit. If any line short-circuits, the whole room loses power. Generally, two or three circuits may be used for sockets: one dedicated circuit for the kitchen, one for the bathroom, and one for the air conditioner.
3. Multiple appliances sharing one socket. This can overload the socket and cause a fire. High-power appliances such as air conditioners, washing machines, and range hoods should preferably have dedicated sockets. In general, four socket groups are recommended in a bedroom; in a living room, one group per 2.5 m²; in a kitchen, one group per 1.2 m².
4. Arbitrary wiring of socket conductors. Power conductors must be copper and of adequate cross-section. In an old house, replace the original aluminum wiring with copper. Aluminum wire oxidizes easily, and arcing can occur at connections. One survey showed that the incidence of electrical fires in homes with aluminum wiring is dozens of times higher than in those with copper wiring. In addition, many families use chased walls and concealed conduits for appearance. Xia Dong reminds that wiring must follow the principle of "live conductor to the switch, neutral conductor to the lamp holder," and a residual current device (RCD) should be installed at the socket.
5. Lack of protective measures for sockets. Kitchens and bathrooms often have water and grease, so a splash-proof box or plastic cover should preferably be installed on the socket faceplate to effectively prevent short circuits caused by grease and moisture ingress. In homes with children, choose safety sockets with tamper-resistant shutters to prevent children from touching the holes with fingers or poking metal objects into them.
In addition, when installing three-hole sockets, some renovation companies often leave the earth wire ineffective, or even connect it directly to the gas pipe. Xia Dong points out that these practices are very dangerous. The earth wire is connected to the appliance casing; once the appliance develops an earth leakage fault, a person can receive an electric shock.
