The installation of an electrical system is the activity that probably takes longer on construction sites, as well as among the riskiest ones for those who work there.
Specifically, inserting the cables into the protective corrugated conduit, takes really a lot of time and a particular care so that the insertion is efficient and above all without damage.
In this long procedure, there is an alternative that allows a considerable saving of time and money, as well as guaranteeing a higher level of security: the prewired conduit.
Let's see together how a prewired conduit is made and its anatomy.
How a prewired canduit is made
As you can easily guess from the name, the prewired conduit is a conduit in which the electric cables have already been inserted, thus allowing a saving of time and money for the manual insertion of such cables.
Prewired conduit exist on the market of any type, such as:
- multi-voltage power cables
- data transmission cables (telephone, coaxial, ethernet and similar)
- cables with low smoke emission
The anatomy of the prewired conduit is quite simple. The outer tube is made of polypropylene and is self-extinguishing.
An advantage of prewired conduit is that they are metrically marked, so it will always be possible to know the length still available in the roll.
The working phases with the "standard" corrugated pipe
In a plant where a standard corrugated conduit is used, into which insert the electric cables, first proceed with the laying of the conduits in the "excavations", the grooves specially created to house the corrugated, then - In a second time - we will proceed to the connection of the boxes that were positioned previously.
Once the conduits are covered with cement mortar, the wiring phase of all the desired cables begins. This phase will consist of inserting a well lubricated cable puller in advance to facilitate the passage, performed by two workers, so as to avoid any damage to the cables inserted (while one pushes at one end, the other pulls, decreasing traction on the cables themselves).
Finally, we will proceed to the connection of what is wired, after the stripping, first to the sockets or to the switches, and finally to the general framework.
This laying method, in addition to an avoidable time expenditure as we will see later, causes a side effect that should not be underestimated.
The inevitable friction that is actually generated by the passage of cables in the corrugated conduit, although facilitated by the lubricant, in addition to risking damage to the cables, generates a "production" of debris and dirt that accumulate in the conduit itself, which in the long run could however, create damage.
Working with a prewired conduit
The wiring procedure with the use of the prewired conduit is much faster, safer and simpler, since it requires fewer steps and fewer materials, therefore less risk of damage to the cables and a greater degree of prevention of the health of the installers involved in the operation.
Once the tracing and the grooves have been made, and the junction boxes are clearly positioned, it will be sufficient to insert the conduits that already contain the cables.
Later, as in the case of the standard corrugated, we will proceed to the connection to sockets and switches and finally to the electrical panel.
With a slightly higher cost than buying the conduit and the wires separately, there are a number of noteworthy benefits, which result in savings, such as:
• lower labor costs, because unlike the laying of the standard corrugated, only one person will be sufficient;
• shorter working time, as not only will one person be sufficient, but it will also take less time for laying, a time that can be used for other tasks.
• greater transport convenience, taking up less space and consequently reducing journeys between the yard and the company;
• greater safety, since there is no rubbing phase due to the wiring of the cables, there is no risk of its being damaged;
• more practical, given by internal lubrication, which makes future maintenance easier