Let’s start with the main point: it’s important to distinguish between levels of qualification and responsibility. There are engineers, and there are installers.
The design of both large-scale and smaller electrical systems is always carried out by engineers. They produce the complete design documentation, based on which the installers carry out all work exactly as calculated and specified in the design, and as approved by the client.
A design engineer’s qualification specifically includes knowledge of the relevant standards, local statutory requirements, as well as the specifications and installation requirements issued by manufacturers of various equipment and components.
Installers, in turn, are expected to be able to read design documentation and carry out installation work to a high standard, in full compliance with the applicable standards, requirements, and equipment specifications.
Personally, I have no difficulty familiarising myself with the local regulatory requirements of any country, as they all either supplement or clarify IEC standards. In fact, I have completed several projects located tens of thousands of kilometres away from where I am based. While my design engineer’s licence is not valid in those jurisdictions, the adaptation of the completed design-essentially the formal confirmation of its compliance with local requirements - was delegated to a local engineering company, which handled the necessary administrative procedures and certification.
The client is free to appoint any contractor they choose to carry out the installation, provided the work is based on the approved design documentation.
Supervision of the works is an optional service, and whether it is required is entirely the client’s decision. It ultimately comes down to the contractor’s competence and the client’s confidence in the quality of their work.
Nobody on forums is going to teach all these procedures or delve into the specifics of every individual case. This is professional work, and nobody is going to do it for someone else free of charge. That’s why I always say that everyone should focus on their own area of expertise and take responsibility for the obligations they undertake.
UPD: More than that, if @CraigK thinks Deye’s all-in-one HV equipment is a simple, straightforward solution that will tick every box, I can shatter those illusions.
He’s in for so many surprises that he hasn’t even begun to imagine, especially at those power levels.
