High Voltage Circuits in Large Industrial Facilities

This paper provides insight into the impact on the facility electrical circuit distribution voltages resulting from the significant increase in power demand of large industrial facilities. Historically the high voltage circuits for industrial facilities were limited to the point of connection with the local utility; however, with the shift in power demand, it is now commonplace for these facilities to utilize high voltage power distribution within the plant boundary. This shift in power demand is primarily related to the need to accommodate an entirely electric driven production model. EPC firms are traditionally accustomed to distribution systems using cable with voltages up to 35kV in which the underground and above ground cable design allows additional flexibility for cable routing. This paper will highlight how underground and above ground designs using large high voltage cable require additional considerations for the planned cable routing, offsets, transition points, pull points, and installation methods. Furthermore, the paper will highlight the advantages of having a joint team of the engineer, the installer, and the cable manufacturer working together early in the project design stage is critical and how this early collaboration and planning can minimize changes in the design as the project moves into the execution phase. The paper will provide recommendations on the discussion points that need to be investigated at the onset of high voltage underground design for an in-plant power distribution system. Lastly, this paper will present a case study of a 138kV underground distribution within a large LNG facility and highlight the key considerations implemented during the design phase which resulted in improved constructability and ease of cable pulling/installation.