A new distributed control system for the consolidation of the CERN tertiary infrastructures

The operation of the CERN tertiary infrastructures is carried out via a series of control systems distributed over the CERN sites (Meyrin and Prevessin). The scope comprises: $\sim$ 260 buildings, 2 large heating plants ($\sim$ 50 MW overall capacity) with 27 km heating network and 200 radiators circuits, $\sim$ 500 air handling units, $\sim$ 52 chillers, $\sim$ 300 split systems, $\sim$ 3000 electric boards and $\sim$ 100k light points. In the last five years and with the launch of major tertiary infrastructure consolidations, CERN is carrying out a migration and an extension of the old control systems dated back to the 70's, 80's and 90's to a new simplified, yet innovative, distributed control system aimed at minimizing the programming and implementation effort, standardizing equipment and methods and reducing lifecycle costs. This new methodology allows for a rapid development and simplified integration of the new controlled building/infrastructure processes. The basic principle is based on open standards PLC technology that allows to easily interface to a large range of proprietary systems. The local and remote operation and monitoring is carried out seamlessly with Web HMIs that can be accessed via PC, touchpads or mobile devices. This paper reports on the progress and future challenges of this new control system.