Offhand, the phrase "extreme load diversity" comes to mind. 167kVA is the largest single-phase transformer I’ve come across, but in my case, always as part of a 208Y or 480Y bank.
Based on typical REA design, I can understand the reluctance to build more poleline. 7200 volts into 167000 voltamperes is less than 24 amperes on the primary. That seems like budgetary belt-tightening taken to a very high degree, but with the state of “deregulation” in the US, it’s not surprising.
One ANSI standard that deals with oil-insulated distribution transformer loading states: “Transformers may be operated above 110°C…for short periods provided they are operated for much longer periods at temperatures below 110°C…” and “Because the cumulative effects of temperature and time in deterioration of transformer insulation are not thoroughly established, it is not possible to predict with any great degree of accuracy the length of life of a transformer even under constant or closely controlled conditions, much less under widely varying service conditions.”
There may be some entertainment value in periodically checking the adjacent watthour-meter demand register, if one exists.
