Maybe its years of working with site generators I have a different outlook to volt drop. The problem is until one arrives on site one tends to expect to see what one has seen many times before, and it is not until one actually arrives do you realise its something new.
When I started to work as an expat then the learning curve became steep. So many things I had never seen before. Some are etched into my mind. I remember like yesterday although it was over 25 years ago, I had a crusher plant where the main motor was tripping overload. Pulling hair out is putting it mildly I had to decide if motor was faulty or something else and I was 10.000 miles from the supplier so ordering a new motor was a big issue.
I was lucky the mechanical engineer arrived and listened to my problem. Was the motor at fault I could not find a fault but shorted winding would not likely show up, or was there something wrong with the plant? Again luck he had come across the problem before, and he instructed the fitter to remove the bearing carrier and take out a handful of grease. I will admit even I was not convinced this would work but he insisted it was tried. He was correct the plant was used so little it had been over greased and that handful of grease removed got it up and running again.
This type of fault needs years of experience to find the answer to. And it is easy to forget how one gained the experience and expect the young to have the knowledge of the older generation.
My father-in-law had a plaque on his desk, it said "These people who think they know it all are especial annoying to those of us that do." It may have been in humour but it has a ring of truth. As one gets older one realises all the errors one has made. Even today I find I need to change my option on items as technology advances.
The main thing one learnt in University was not how things worked, but how to use one brain to assess how it might work, and to adjust ones ideas to the results of an experiment. The person who gets all the answers right is not trying to expand his knowledge.
This is why feed back is so important. For the poster to say what was found to be the problem really helps us understand. pobody's nerfect we learn from mistakes. It is however better better if we can learn from others mistakes rather than trying to re-invent the wheel.