What do the protection function numbers mean? In single line diagrams and other documents depicting protection details you can see various numbers. These numbers are also called ‘ANSI codes’ as they are defined in the ANSI/IEEE standard. What do the protection function numbers mean? You have surely seen them: the Read more…
Protection of VFD-fed motors How to properly protect an inverter-duty variable-speed electric motor? What protection is covered by the VFD? What shall be done externally? Which protection elements are most suitable? The article on protection of VFD-fed motors brings the answers. General considerations System and equipment protection is of crucial Read more…
VFD transformers: Differential protection Differential protection of VFD transformers might be a controversial topic. The more a reason for us to bring it up, explain the principle, describe the advantages and drawbacks and provide our view and recommendation for the users. We hope that this article will be useful source Read more…
Protection of VFD transformers In the introduction to this series we have explained the differences between a distribution/power transformer and a VFD transformer [1]. Due to different design, construction and operation of VFD transformers the protection requirements shall be adapted as well. While many end users, system integrators, EPCs and Read more…