The cooler of each oil immersed power transformer is equipped with a nước rò rỉ detector. As the pipeline of oil immersed power transformer cooler is a double-layer pipeline, when the pipeline inside the cooler heat exchanger leaks, the nước rò rỉ monitoring device will send an alarm signal, and observe whether there is water leakage by observing the inspection window on the water leakage detector during rotation.