When it comes to electrical installations it is inevitable to refer to the wiring: despite being a
routine activity, it is very easy to make mistakes, or not to notice any errors.
This is because it takes for granted an activity that requires a lot of attention and a set of basic
knowledge sometimes ignored to get the job done as quickly as possible.
A professional often focuses on practice, leaving out some fundamental theoretical concepts for
perfect placement: here are some tips to refresh your customers' memory.
Wiring: the best advice
For safe installation and use, it is important to operate with the right temperature: a common mistake is, in fact, to pull the cable when it has been stored in a cold environment.
In this situation, the insulator, being formed of thermoplastic or rubberized material, can crack if subjected to bending or a minimum tension due to the draft.
To remember that, in the long term, a damaged insulator is like there was not even.
The presence of humidity can significantly influence a cable and significantly affect the characteristics and the protective sheath.
The action to consider is to seal the ends of the cable with an effective method.
Rubber and plastic insulation in some cases may be sufficient, but many times it is the same construction company that requires them to be protected by the application of a heat shrinking device until the construction site has reached the safety threshold.
The tension during threading
We mean the force applied to the cable during the wiring action. It is given by several variables:
- the direction of the applied thrust and how long it takes place,
- the weight of the cable,
- how much friction is present between cable and conduit,
- the number of conduit curves in which the cable is pulled and their circumference,
- the type of cables inserted in the conduit and their predisposition,
- the temperature of the surrounding environment, especially when it is cold.
Since the fundamental part for an installation is the wiring phase, it is essential to plan it carefully
using the right formulas for the friction constants.
The type of circuit and its size are another of the key elements for an effective installation: in fact, a cable can easily be damaged during installation if the circuit in which it is to be inserted is of the wrong size. The solution is, where possible, use a larger conduit.
Another aspect to consider is the presence of debris inside the conduit: the most common method to free the rubble is to use compressed air or special tools.
Finally, but fundamental, is access to the conduit: at the input there must be no tension and the cable must be inserted in the conduit perpendicular to the input surface.
To work with an “used” wiring probe for the wiring process may be a mistake because it is very
important that it is kept in good condition.
Let's talk about a probe that must be clean, dry, without knots and cuts that make it not optimal for its use, because its condition is the first factor that influences the success of the process, even before the correct calculation of the tension and the its application.
The type and size of the protective sheath can influence the best conduits.
For example, some rubberized insulators are struggling to be inserted into a PVC pipe, even if aided by the lubricant, as the latter loses some of its characteristics over time, a problematic situation especially in the event of cable removal at a later time installation.
The best are those based on water, which allow an easy use and a subsequent faster cleaning.
Applying it constantly during the threading would be ideal, but due to the expense it is also acceptable at periodic intervals of time, depending on the type of conduit and cable.
Precabled conduit: the most suitable choice
The wiring process is not quick, nor a simple one: the variables to be considered and the tools to be used are many and each has its own characteristics, as we have analyzed above, which, if not observed, can lead to failure.
And yet, an alternative to avoid worrying about all these aspects is: the precabled conduit.
It is a corrugated tube that already has the cables inside, allowing an immediate and simplified
use of the product.
It can be proposed for any type of installation. thanks to the configuration that makes it suitable for the most diverse situations: from external use to internal systems, its main strength, in addition to clear advantages in terms of timing and comfort, is safety, both as regards the electrician and towards the final user.