... .5KV 3.Core-folled and Sealed Tank 4.ISO9000. BDT-S9,S11 TransformerFeatures of Products1.Reliable structure.Such as these improvement ... inspection.3.Good Technology and Economic PerformanceCompare with S7 series,S9 series reduces the no-load loss by 10%,load loss ... result,the operating cost will drop by 19%.Improved from S9 series,S11 series reduces the no-load loss by 30 ...