Are you talking about the infamous "Medical City", Eddie? It had a 110 V system in place, did it not? But with 220 V for the heavy stuff like the A/C's, cookers, and washing machines, most likely. So yes, your "earth" was probably off a centre-tap as I mentioned above.
All those drawings were there, and duly handed over, believe me. But there would have been many more handovers since then, I should imagine! But I'll bet that the
Al-Haras Projects Department has a pristine set hidden away somewhere.
As an aside, I would be more interested in hearing about keeping those "As-Built" drawings updated in line with all the changes that must have been made ... including the one you've just mentioned!
