1. Construction drawings before construction
Before construction, it is necessary to have electrical (strong and weak) and plumbing design and construction drawings.
2. It is strictly prohibited to expose wires
It is strictly prohibited to lay wires directly in walls, floors, under floors, or ceilings without any protection.
3. Wiring conduit should be distinguished
Lines with different voltages, circuits, and signals are strictly prohibited from being threaded through the same conduit.
4. The installation of lighting fixtures should be carried out after the painting is completed
When installing lighting fixtures on brick concrete structures, the use of wooden wedges is strictly prohibited, and hooks, bolts, or expansion bolts should be used instead. The number of bolts (or screws) used to fix the lighting fixtures should not be less than 2. Luminaires shall not be installed on combustible components.
5. Installation of switches for lights and electrical equipment
The switches of lights and electrical equipment must be installed on the "phase line" (i.e. control phase line), otherwise after the switch is turned off, the lights and electrical equipment will still be charged, which can easily cause electric shock incidents.
6. There are two protection methods for the electrical system
Grounding protection and neutral protection are generally adopted in China at present. Note that in the same system, it is strictly prohibited to adopt two protection methods simultaneously, otherwise it may cause safety accidents.
If the lamp is equipped with a screw head, the central spring tongue of the screw head should be connected to the control phase wire.
8. Protection at the interface
The interfaces of each line should be smooth, and the board connections should be firm. The interface box of the power supply inlet box should be protected with a protective ring (locking nut).
9. Curvature of conduit elbow
In order to update and maintain the wires in the future, the curvature (i.e. cold bending radius) of the bend at the turning point of the conduit buried in the wall, underground or ceiling should be 5-10 times the diameter of the conduit.
10. Do not connect wires inside conduit
It is prohibited to connect wires inside conduit. If the length of the wire is not long enough and needs to be extended, the joint of the wire cannot be inside the conduit. Generally, wiring should be done in junction boxes such as switches, sockets, and lamp heads.
11. Selection of conduit
The conduit should be of a certain size (thickness), which not only allows the wire to pass through, but also leaves enough space to dissipate the heat generated by the wire when passing through high currents. The ratio of the cross-sectional area of a general wire to the cross-sectional area of a conduit is 1/3 to 1/2. It is strictly prohibited to block the conduit tightly with wires.
12. The water supply pipe can be made of PP-R pipe or copper pipe.
13. Water supply pipe inspection
The concealed water supply pipeline must be strictly inspected to ensure that all connection parts are installed tightly, firmly, and in the correct direction, and then undergo a water pressure test. After a period of water testing, it can be concealed. The pressure test index is generally suitable between 0.8mpa and 1.0mpa.
14. Precautions for installation of drainage pipes
The horizontal pipeline of the drainage pipe should have a certain slope, and the socket connection should be tight to ensure no leakage. The spacing between the brackets and hangers for fixing the pipeline is reasonable and firm.
15. Installation position of sanitary ware
The installation position of sanitary ware should be accurate, and the support and bracket should be installed flat and firmly. The floor drain should be installed at the lowest point of the ground and recessed 5mm into the ground. The connection seal between the toilet and the ground or pipe should be made of oil mud or silicone, and cement should not be used, as cement can expand and cause cracks and damage to the bottom of the toilet.
16. Location of hot and cold faucets
The hot water faucet in the cold and hot water faucets should be installed on the left side. Electric water heaters should have grounding protection devices. When first used, the air inside the tank should be removed and filled with water before being powered on and started.