The use of pre-made compact post is based on the use in the ground open ring network, and in order to place the post in the network ring, the compact medium pressure switchboard must have 2 disconnectable disconnectors under load and one fusible disconnector for transformer protection.
Considering the load density in crowded urban areas and the existing experiences for diversification, the capacity of these substations is considered to be 800 KA.
For special plans related to industrial and commercial customers with high load that require the use of dedicated substations with a capacity higher than 800 KA . The secondary relay is used to protect the transformer.