Leakage Current through Insulator
Thermal images show hotspot (white) typical of leakage current through core of stand-off insulator.
Defective Metering CT’s
Thermal images show overheated metering CT. All phases under similar load.
Defective Equipment
Thermal images show overheated oil circuit breaker. Condition typical of low oil and/or internal hot spot(s).
Something Else
That has something wrong with it.