The Short-Circuit Testing Liaison STL provides a forum for international voluntary collaboration between testing organizations. The main purpose is the harmonized application of IEC and Regional Standards for the type testing of electrical power equipment. LCOE as a member of AELP (Spanish Association of Power Laboratories) is attending the STL technical meetings every year since 2016, where technical papers presented by experts from member and applicant laboratories are discussed. This year LCOE presented one technical paper on the need for an STL interpretation guide for conducting short-circuit and temperature-rise tests on single-phase station service voltage transformers, SSVT, in accordance with the new IEC IEEE 63253-5713-8 Standard, published in 2024. Finally, on Thursday 13th November, the participants visited the HITACHI Energy facilities placed in Ludvika, including the High-Power Laboratory, affiliated to SATS, which started short-circuit testing in 1933 with the installation of its first short-circuit generator, at that time the largest in the world.