A practical approach for sizing a water-cooled bus

The sizing of electrical bus is an iterative exercise. The process logically starts with the identification of materials based on performance requirement, budget, design standards and fabrication/installation codes to be met. The decision on sizing multiple forced-cooled buses within a space-restricted envelope at a public regulated facility has it´s own challenges. The first iteration in sizing is critical for the subsequent calculations like stress/seismic analysis, EMF effect, cooling package, life cycle cost etc. This paper provides a baseline bus sizing calculation that can also be used as a verification tool for procedural validation of software calculation, if any. Design of bus system for a single-phase electric furnace with multiple pairs of electrodes will be demonstrated with considerations for material selection, current carrying capability, inductance calculations, voltage drop, cooling requirements and the size of flexible jumpers (shunt) between the bus and the electrode or its extension.