This relay is installed in the oil-filled conservator tank of the transformer and detects faults such as internal short circuits or insulation failure. At EMR Global, we design advanced protection systems that help industries keep their transformers safe, stable, and performing at peak levels. A transformer. Core idea: Transformer protection detects electrical, thermal, pressure, gas, and insulation-related problems before a transformer failure damages equipment or spreads through the power system. While there is some validity to this approach, there are many other issues to be considered.