Defines type, production and optional test on thyristor valves used in thyristor controlled reactots (TCR), Thyristor switched reactor (TSR) and thyristor switched capacitors (TSC) forming part of static VAR compensators (SVC) for power system applications. the requirements of the standard apply both to single valve units (one phase) and to multiple valve units (several phases). Clauses 4 to 7 detail the type tests, clause 8 covers the production tests, clauses 9 and 7 detail optional tests. The contents of the corrigendum of December 1999 have been included in this copy. This consolidated version consists of the first edition (1999) and its amendment 1 (2003). Therefore, no need to order amendment in addition to this publication.