Electrical – Requirements for electrical wiring project for a house

electricalwiring

I am remodeling a house and need to put in place a completely new electrical wiring along with security and surveillance systems (wiring for motion sensors and CCV cameras outside).

I am going to hire an engineer for the project. However I'd like to understand the typical requirements for such a project to be better prepared for my conversations with contractors.

My idea is to ask for a CAD project with a set of diagrams/views. Specifically, the following:

  • Blueprint with all the lights, sockets, switches, meter and
    distribution board placed on the floor plan.
  • Schema listing the cable types and maximum power allowed per circuit.
  • Distribution board plan.
  • Exact layout of cable on walls/ceilings including enclosures, where needed (2D/3D?).

Once the above is complete, I would expect the engineer to control the execution of the plan and test the wiring once it is installed.

Overall, I want to accomplish 2 things:

  1. Ease of maintenance for years to come.
  2. High quality electrical wiring to be built.

Questions I have:

  • Are there any important artifacts/documents I should be asking the engineer to provide?
  • Should I be asking an electrical engineer to also design the wiring for CCV cameras and motion sensors or is this job best left to someone else?
  • Perhaps I am over-engineering and the above list can be simplified?

UPDATE
I am located in Europe and not concerned much with the local regulations as I am sure the requirements for regulators will be met at the end.

Best Answer

I think you're over-engineering it.

Nobody really bothers specifying cable locations that precisely for electrical wiring. There are rules to protect electrical wires from damage, but they don't involve precise mechanical drawings of the build.

Further, you aren't going to be able to find anyone to install it to your diagram. Electrical engineers don't do house wiring, and electricians who do house wiring don't follow diagrams precisely like that, they just throw it in quick-and-dirty. Wiring is protected from damage, but using different techniques - for instance in North America there's a rule that you can go in 1-5/8" (40mm) without concern because wires and pipes are either guaranteed to be deeper than that, or will be guarded by a metal warning plate.

However, since you are aiming for top quality and easy maintainability, there is definitely something you should think about: Metal conduit. This is where you lay a type of pipe designed for electrical service (and some of it pipe-fits quite easily) and then you run the circuits in the pipe using individual wires (i.e. Not with multi-conductor cables). The piping does several things for you.

  • It physically protects the wiring from subsequent mechanical work, similar to metal guard plates.
  • Wiring grounds is often unnecessary - the pipe is it - so 30% of your wires just go away.
  • It allows easy wiring generally - conduit wire is much easier to work with.
  • It allows multiple circuits per conduit (to a limit) - allowing economy of conduit.
  • You can expand or customize it later.
  • If wire damage or splice failure occurs, does a good job of protecting you and preventing fire or shock - it nearly serves the function of American style AFCI breakers.
  • It is the highest quality installation you can get.

Generally, data cables are not allowed in mains electrical conduit or junction boxes, due to the risk of a wire melt putting mains voltage on equipment not rated for it. (Fiber-optic is OK). However you can lay parallel conduit for telecomm, and that conduit can be plastic.

Suffice it to say, designing a good conduit system is a very good outlet for the high standards you are setting.

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