For the transformers testing, e.d.c. proposes the system ATT320/W available in various versions, suitable for singlephase and/or threephase transformers from few Watt up to 100KW, from 4 to 36 terminals (with standard steps up to 1KW – 10KW – 100KW, 4/8/12/16/24/36 terminals). The systems allow the performance of safety tests, functional tests and – as options – of many other additional tests and, among all, are particularly suggested the partial discharges. The systems can be integrated into an automatic line or they can be designed for operator use, eventually associated to work benches external, integrated, single station, double station, multistation, rotating table, ...