Working on behalf of the incumbent Chiller Maintenance Contractor, we were asked to Retrofit a new Sabroe Unisab III Control System to an existing older Sabroe Unisab II System. The 1.1 MW Cooling Capacity Ammonia Inverter Screw Water Chiller took some planning, testing and patience to implement. There were marked wiring differences between the two versions of controller which the manufacturer had no documentation on.
After recovering the ammonia from each of the 3 systems in turn, retrofitting all system Temperature & Pressure Transducers and Control System, we compiled and issued an As Installed Wiring Diagram of the retrofit. We commissioned the new Controls and added a North Compass Node gateway between the site Cylon BMS System to the Sabroe Unisab III Network; allowing control & telemetry transfers between networks.