Pepco Date Exelon Utilities Transmission Bus Configuration Design Philosophy PDF 5.19.2021 EU Transmission Facility Interconnection Requirements PDF 1.1.2021 PHI Technical Considerations for Generation Parallel Operations PDF 10.13.2016 PHI Preferred Vendor List ZIP 9.23.2018 PHI Operations and Modifications Requirements PDF 10.10.2011 Pepco - Facilities Study Approved Vendor List PDF 11.16.2018