The rise and research of pluggable electrical installation in concrete

Published on 7 december 2022 19 October 2022 Reading time : 6 minutes

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For years, pluggable electrical installation in concrete was considered impossible. In our previous blog you will read how Isolectra proved that it is not impossible but rather a possible challenge. Pluggable electrical installation in concrete is now widely used, especially in residential building. However, it was definitely a challenge. In cooperation with Wieland, our supplier of the RST20 electrical installation system, we went through an intensive testing and certification process. In doing so, we did a lot of research to find out and prove that pluggable electrical installation in concrete is possible. In this blog, you’ll read more about all the research we did before pluggable electrical installation in concrete could actually be put into practice. .

Casting installations in concrete 

Several companies, especially in prefab concrete construction, had for some years been looking for ways to build faster, more efficiently and plan better/easier. A concrete question from the market came to us regarding the laying of installation cables in escape routes. These should be classified with a high fire rating. This involves more expensive cables, and fire seals have to be made. All in all, it is an expensive process. To avoid this, Isolectra was asked the question: ‘Is it not possible to pre-cast these electrical systems into the concrete?’ 

This would ensure that no air can reach it (and thus no need to use a fire class B2ca cable) and that no penetrations would have to be made fire-tight. 

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The study 

As mentioned above, driven by market demand and our own innovative strength, we partnered with Wieland to study the feasibility of pluggable electrical installation in concrete. A number of things have happened and are in motion: 

Special cables 
Normal cables should not be cast in concrete. This is because the cable should not affect the concrete and, vice versa, the concrete (the chemicals) should not affect the cable. 
The first step we took was to develop a system with a special cable suitable for casting in concrete. 

We started coming up with some tests that we could unleash on both the cables and connectors. With this we started to find out whether the cables and connectors are suitable for casting in concrete. Some examples of factors we tested are: 

  • Vibrations: we tested whether the joint could withstand vibrations occurring in the concrete. 
  • Temperature: can the connector withstand certain temperatures? 
  • Shrinkages: can the system deal with them? 
  • Electrical strength: given that the system must be capable of functioning well in concrete for a very long time, we conducted electrical endurance tests. 

For all these tests, we did not do this in the same way as we do for normal plug connections. We conducted much more severe testing, purely to generate greater certainty. 

Test lab 
Isolectra made a test wall at the time and cast the electrical systems. All tests were done on this wall. The test wall was transported to Wieland including cast-in-place systems. The testing itself took place at Wieland’s test lab. 

In the end, we also started testing in practice. For example, we built some walls with a wall manufacturer. We started building and testing these on site. This went off without a hitch. On this site we partnered with Koopmans and Van Losser to build five homes. Strictly speaking, test homes is not the correct name here as these actually became genuine homes. So this really had to be done properly. 
The process of getting this right went broadly as follows: 

In collaboration with the electrical contractor, we designed the house/units. 

All the necessary materials were then made at Wieland. 

After arrival, all materials were extensively tested. 

Together, we built the materials in kit form as they should be laid in the wall. 

We once again carried out tests and readings, cast it into the wall and then carried out more tests and readings. 

Transported to the construction site and carried out more readings. 

System assembled, connected and more readings were conducted. 

Completion and, of course, one last round of readings. 

Overall, it was an intensive process with a lot of time specifically spent on carrying out tests and readings. However, this yielded the desired result: we never encountered any problems and the houses have been standing for several years now and are functioning well! 

Benefits of pluggable electrical installation in concrete 

The main advantage of pluggable electrical installation in concrete is that the amount of work on site is reduced compared to conventional installation. After all, it involves using ready-made cables with ready-made connectors and distributors. This eliminates the need to lay conduits in a wall or floor, involving just ready-made cables. A wall with a cast-in-place system (with cables, cable boxes and plug connectors) is transported to the building, installed and the electrical system is connected using plug connectors. This basically finishes the installation. After all, there is no need to fit conduits any more. 

In summary, this ensures: 

  • Faster construction 
  • Greater predictability: work becomes easier and more efficient for electrical installers to plan. 
  • Relocation of work from construction site to factory environment. This leads to: 
  • Fewer errors, as it is easier and more efficient to work in a factory environment. 
  • Reduction of CO2 and nitrogen emissions. 
  • Planning for all disciplines becomes more reliable and easier. 

Interested in learning more about our experience with pluggable electrical installation in concrete? We’d be delighted to share them! Do not hesitate to contact us. 

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