IEC Standards BS IEC 61378-3-2015 pdf free download – Converter transformers Part 3: Application guide BS IEC 61378-3-2015 pdf free download - Converter transformers Part 3: Application guide. Industrial units with tertiary windings loaded with filter and compensation are covered in IEC 61 378-1 :201 1 , 5.7. It should be noted... 02-12 Download Now