... ; GB1094.3,5; GB/T6451-2008; 3)One year warranty Energy saving oil immersed 3 phase transformerProduct introductionS9/S11 series of 3-phase oil ... industries, mines, petrochemicals and agricultures. Compared to S9 series of products, S11 series boast lower no-load loss, dropped no ... oil volume change which can be adjusted using the elasticity of the transformer oil tank.Compared to S9 transformers, S11 ...