There are different methods are used to lay cable in the electrical systems. Normally in the electrical system, most of the high voltage cables are laid under the ground. There are so many parameters to consider while the laying of these cables. In a practical situation, there are three main Cable Laying Systems are used commonly for laying these under ground cables which are. (i) Direct System, (ii) Draw in System and (iii) Solid System. The methods of mentions show in below with its unique advantages.
Direct System Cable Laying Systems
The direct system of cable laying involves the cables laid in a cable trench and after that, the cable is filled with soil. The trench also cover with bricks or concrete slab then again fill with soil. The layout of this Cable Laying Systems can show in the figure.
The system of cable laid with a serving and it’s enough to protect the power cable from corrosion.
Since this direct System method is cheap and simple this is one of the most common methods which use for the underground power cable.
The hazard which can occur from excess heat dissipation can also be avoided by the arrangement.
The layout system is good with vibration so this layout can also use where heavy traffic areas which prone heavy vibrations.
But there is some disadvantage of this cable layout system too which as the load extension can only perform by installing a cable in the new trench. and this new trench construction lead an additional cost for the new cable installation.
Draw in System Underground Cable Laying
Draw in system cable layout methods is widely used for heavily populated areas such as urban cities and towns.
Normally the cables are layout in ducts or pipelines on the ground with certain manholes. The layout arrangement of the draw in the system is shown in the figure.
If we consider about this cable laying systems, it goes unique advantages over other power cable laying systems.
It is really easy to maintain and repair the cable on this arrangement.
When you need to add another cable additional you can able to install them very easily so the installation cost for new loads is really cheap.
Any alteration or addition of new cable can perform very easily without digging ground.
The solid system of cable laying is mainly performed where the cable is laid in the wood, cast iron, or another nonsoil surface. Normally cable is laid in the manner which provides good mechanical strength to cables.
This system is much appropriate for solid based systems. Normally the cables are filled with bituminous materials for providing protection and avoid heat dissipation. Then another Asphalt cover layer around the cable and bituminous material area for further protection.
The system is expensive compare to the direct laid system and heat dissipation capacity is not much good compere with other systems. But for toughing material woods are much cheap so it is widely used by considering the economical impacts.