Underground cabling, as the name explains itself is an approach to lay cables under the ground. It is highly reliable way of networking and power transmission. But still, there will always be a need of quality in working, the cable quality and branching to ensure reliability. There are three main methods which is also a part of our working strategy to spread cables across the country.
- Direct laying
- Draw-in systems
- Solid systems
We explain below how we do it and what the ways to from these methods are.
- Direct Laying
Direct Laying – The method is most popular due to the fact that it is cheap and fast. It requires very less level of expertise, but it does require proper machinery to execute the project. The cables which are placed in this method require servings of Bituminized paper and hessian tape layering over it to provide protection. The protection for the cables is required due the corrosion and electrolysis effect of the direct soil and sand contact with the cables.
We follow a prescribed procedure to put cables underground with this method. The trench goes around one and half meter deep into the earth surface making almost half a meter wide dug. Then this trench is covered with 10 cm thick layer of fine sand so as to absorb the moisture from the bottom soil. The cable is put over that and then about 10-15 cm of sand is poured over it. If any further cables are laid then we put approximately 30 cm gaps between these cables to protect from any kind of heat exchange between the cables. And If there is any fault in one cable, there should be no damage to the other cable. Over all these setup, cover of bricks and soil is put to cover the trench and leveled to the neighboring soil.
This is a cheaper method for both us and our clients to build and simpler for us. Then the heat generated in this type is directly dissipated into the soil so there is no requirement for any kind of heat sink. There are disadvantages too for the cheaper methods though. There needs to be total evacuation of local sand from the location to install the cables, alteration is difficult in such case, the maintenance cost gets higher on any damage and difficult to find the error location too. Usually preferred in open landscape areas where no issue on complete digging.
- Draw-In System-
Draw-in System – A cast iron or concrete pipe or ducts are put in the underground with the manholes available at a specified location to route the transmission cables. The cables are protected by jute or Hessian tape and then pulled into the pipes from the manholes. We take care of all the safety measures; we put a third duct too to meeting any future improvements in the cablings. These are usually used in the start to put pilot wires and connections.
This type of underground cabling will help in repairing, adding and altering the cable network though the manholes in future without needing to dig complete and without re-excavation. The cable joining becomes simpler because there is no need of any armoring, and hence the maintenance cost goes down. In fact, there are lower chances of any kind of fault occurrence due to deployment of heavy loads on the top soil. Yes, the initial cost gets heavy in such case and the heat dissipation is reduced due to closed chamber.
The Solid System –
The Cable in such system is by putting a trough in cast iron or stoneware, asphalt or wooden block, making the cable go through it. The cable passing through these troughs is filled with bituminous of asphaltic compound and finally covered from the top. The cables are so laid in such pattern that just the lead covered trough can protect from all the mechanical loads it gets. In this also the cost of both building and burial of the cables in the encasement gets heavy on initial cost. But it does protect cables from any damages from the overheating and short circuit failure in any one of the wires. Although it requires a skilled set of labours to work on the site and the weather conditions also needs to be favourable to execute the project. The heat dissipation in this type of current carrying capacity of cable is reduced.
We can conclude by saying the underground cabling is one of the best aspect of working with GPC Infotech. We have been working on all the systems of Underground Cabling of the cables with precision in various states across the country. Our current projects are going on in Gurugram and Haridwar and we are looking for many other projects to come in future.