The transformer sold by the exporter can operate according to the nameplate under the specified cooling conditions, but the top layer oil temperature shall not exceed 90 °C. In order to prevent the insulation aging of the transformer, the top oil temperature should not often exceed 85 °C. The alarm setting is set at 80℃. Many exporters of advanced oil-immersed distribution transformers have their own cooling methods. Oil-immersed transformers usually use oil-immersed self-cooling, oil-immersed air-cooling and forced oil circulation cooling methods. This is how exporters of advanced oil-immersed distribution transformers control the temperature generated during operation of the transformer