The accelerated energy transition is currently causing serious bottlenecks in the energy supply in the Liander service area, with undesirable social consequences and related public attention caused by broad concerns in society. Against this background, Alliander wishes urgently to purchase a retrofit solution for existing Magnefix MD medium voltage switchgear installations for enhancement with measurement of current and voltage on all MV cable fields. Maximizing the hosting capacity of existing grids is an important strategy of Distribution System Operators (DSOs) to keep pace in the facilitation of renewable energy sources and electrification of loads. This requires more real time information from the network and solutions for autonomous transport capacity management. This focusses on a digitization solution for the unique design of the 12 kV Ring Main Unit (RMU) switchgear type Magnefix, which has been installed in the DSO grids since the mid-fifties last century. Magnefix represents the majority of existing RMU installations in the Netherlands. Therefore, a low effort digitization upgrade is very important for the Dutch DSOs as enabler for maximization of the hosting capacity of the MV grid. The digitization solution consisting of replacement of the switch cap to an intelligent cap, which is capable of neutralizing interference caused by other phases and bays. The replacement of the cap is a standard switching action. A standard open Modbus interface is used for interfacing to the DSO control system. The needed solution shall measure the size and direction of the electrical current, and shall measure the voltage, including a direction-sensitive short-circuit indicator. At least the following measurements shall be supported: • Voltage and phase angle per phase, with an accuracy sufficient to determine the direction of both the actual current and short circuit current. • Magnitude and direction of the current per phase, with an <5% accuracy in the range of 50-500 A and a <10% accuracy in the range of 25-50 A. This accuracy also applies when low current is running through one field, and nominal current runs through adjacent fields. • Directional short-circuit detection per phase incoming/outgoing and a combined message per field in a register of 1, 2 or 3 phase faults. The measurements results shall be available on a Modbus RTU standard serial interface for the purpose of system integration. An essential aspect of the retrofit solution is safe and easy installation with the replacement as easy as a standard switching action of the Magnefix MD installation. Other prerequisites are a technical lifetime of at least 15 years with an availability of 95% or better.