Sanger Substation Upgrade Engineering & Design

CLIENT: Algonquin Power Sanger LLC

IEC Corporation performed an electrical substation evaluation, developed the design package (70 MVA, 115kV/13.8kV), and managed procurement in support of the PG&E Sanger-Reedley 70 kV to 115 kV transmission line upgrade at the Algonquin Sanger Cogeneration Facility. As part of this project, IEC was also asked to perform and arc flash analysis for the facility.  To perform the study, IEC calculated short circuit currents in modeling software at the 70KV, 13.8KV, 4.16KV, and 480V bus. Those values were used to calculate the arc flash energy and boundary at the various bus voltages. The duration of the arc flash current was based on the types of existing and new fuses, breakers and relays settings. The Arc Flash calculation was based on IEEE Standard 1584 2004 Edition and NFPA 70E 2004 Edition. The final report provided the client with the proper Personal Protective Equipment (PPE) to be worn by qualified people to operate the electrical equipment. The minimum level of PPE was recommended based on the tasks performed at the various voltage levels. IEC also recommended a follow up study of the whole facility to update all the equipment including the non-repower project equipment. Our engineers also recommended upgrading the old ABB overcurrent, neutral/ground relays for the 70KV breaker CB101 due to limitations preventing the use of PGE’s instantaneous settings, which could cause nuisance trips during grid faults.