Browser-based relay protection tools, learning modules, and technical references for protection engineers. This handbook covers the code of practice in protection circuitry including standard lead and device numbers, mode of connections at terminal strips, colour codes in multicore cables, dos and donts in execution. Also principles of various protective relays and schemes including special protection. Delgado Relay Protection Reference is an interactive engineering workspace where protection engineers can review fault behavior, test relay concepts, and move between tools, visual explanations, and technical notes without leaving the browser. Open practical studies quickly without waiting for. Relion protection and control relays for several application reduce complexity. Long term cost reduction (TCO) for trainings and maintenance by reduce variety of relays A fast and selective arc fault mitigation for air-insulated LV & MV switchgear and Relion protection and control relays and sensor. Is it possible to learn protection relay testing without the hardware? I do all kinds of typical HV testing - AC/VLF hipot, IR, IPF, winding, DRM, partial discharge, SFRA etc etc.