IEC 60143-4:2010 specifies testing of thyristor controlled series capacitor (TCSC) installations used in series with transmission lines. This standard also addresses issues that consider ratings for TCSC thyristor valve assemblies, capacitors, and reactors as well as TCSC control characteristics, protective features, cooling system and system operation. This part of IEC 60143 is to be used in conjonction with the following standards: IEC 60143-1:2004, IEC 60143-2:1994 and IEC 60143-3:1998.