Like topgroove said, we need to piece things together. It's hard to tell in the pic, but to me, this looks like a larger sub with maybe two or more transformers in it. If they went and tied two substation transformers together and that close together they would have had to have the secondary voltages as close together as possible approximately 0.7 volts on the test point in the LTC cabinet. I have yet to work on the inside of a Reinhausen and don't know exactly how they operate but if they are anything like an AC or Siemens there is the possiblity that the taps were askew inside even if the voltages matched since your test points are only on one phase. The difference of potential on one phase could cause catastrophic events to occur.
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