Lago Vista Voltage Conversions
This project was to convert Lago Vista Substation’s voltages of 6 feeders from 7.2kV to 14.4kV to improve reliability in the area. This project covered 65 miles of overhead distribution lines and 18 miles of underground distribution systems, 600 transformers, 50 reclosers, 12 sectionalizers and 3 capacitor banks, which had to be converted to 14.4kV. For the “make ready” portion of the work, M&S Engineering personnel performed field investigations, GIS mapping and took inventory of the existing systems, then provided detailed design work for the modifications to spacing, framing types, insulator arrangements, cross-arms and dual voltage equipment (7.2×14.4kV) required to accommodate the higher voltage, yet remain in operation at 7200v, until “day of” switching. Sectionalizing and planning portion of the work was closely coordinated with PEC operations and maintenance personnel to allow continuous operations while construction crews performed their fieldwork. M&S provided inspection services during construction and installation activities to ensure adherence to design and PEC standards.
Once construction activities were completed, M&S personnel then provided customer outage notifications (mail outs & phone calls) for 6 separate ½ day outages that would be required for “day of” conversion activities. To minimize customer outage times and interruptions, actual “day of” conversions were performed on 6 different days spanning 8 months (3 spring, 3 fall). M&S planners organized field crews, provided switching operations, which included use of a mobile substation and back feed for critical load customers. M&S personnel provided tailboard safety instructions to line crews, job hazard assessments and traffic plans for each ½ day outage. Additionally, M&S personnel coordinated marshalling activities, traffic control, flaggers and catering at 4 different locations to accommodate 50+ bucket trucks and construction crews.