(1) buried directly in the ground, this is the most common and economical laying method.
(2) Laying in the cable trench to lay various cables.
Although the cable trench was larger than direct burial at the time, it was convenient to monitor the temperature and take ventilation and cooling measures to improve its heat dissipation conditions.
Besides, cable trench also has the advantages of easy cable maintenance, the new installation, the replacement and prevention of damage by external force and the detection and repair of faults.
(3) Installed in the cable tunnel, when laying cables in areas where there are many outgoing cables in power plants or substations or where there are many parallel installations (as 20 ~ 40 or more), cable tunnels should be considered.
Although the construction of cable tunnels has a large investment, a long construction period and expensive building materials.
It brings many problems such as ventilation, fire prevention and water leakage prevention, has the following advantages:
1) the stretch of road (Hall) occupied by the cable line is greatly reduced.
2) Reduce external force damage and mechanical damage to the cable.
3) Eliminates chemical corrosion of the protective layer caused by harmful substances in the soil.
4) It is quick and convenient to repair or replace the cable.
5) New cables can be added at any time without having to dig up the road.
(4) Laying in the cable duct, when more cables pass through the urban street, the direct pressure of the buried cable is large and it is not suitable for building the cable trench and tunnel.
The cable duct can be built and the cost is less than that of the tunnel, but there are many. The advantages of the tunnel do not have to be taken into account for fire protection.
(5) Laying over cable tray is a new way of installing cables in the plant area. There are many pipes in the plant area (especially in power plants or chemical plants).
It is very difficult to build trenches for cables and, often, due to the operation of the steam pipes. Water runs to damage the cable, so cable supports are installed in the factory area instead of cable trenches.
(6) aerial installation. Due to the development of plastic cables in recent years, the weight of the cables is reduced, and the way of hanging the cables on the suspension wires is gradually applied (or fix them on the tower).
Compared to cables buried underground, aerial wires are susceptible to external influences and are not aesthetically pleasing, but construction costs are low.