1- Insulation coordination studies are essential in order to achieve optimum reliable systems.
2- Substation equipment should have been fully typed tested to the relevant latest IEC Standards
3- In future spark gaps and arcing horns to be discouraged for usage as element s for over voltage protection in substations.
4- It is strongly recommended to use reliable and economic metal oxide surge arrestors.
5- Polymeric (silicon rubber) insulators up to now seem optimal for the GCC countries, however still more exchange of experience regarding the long-term performance is required.
6- Modern analysis techniques should be used for system studies regarding over voltage protection of air insulated switchgear (AIS) and gas insulated switchgear (GIS) substations.