Transmission Loop Conversion to Underground

To increase system reliability, Puerto Rico Power Authority (PREPA) is putting its 25.4 mile 115-kV overhead transmission loop around San Juan underground. The project was divided into five phases; Burns & McDonnell assisted in the engineering of Phase I and Phase IV.

Phase I of this project spans 5.4 miles from Monacillos Substation to Hato Rey Substation and Phase IV spans 5.9 miles from Bayamon Substation to Monacillos Substation. The system includes a new 115-kV circuit, a future 115-kV tie in, and a future 38-kV circuit.

Burns & McDonnell worked in conjunction with the turnkey team to provide a seamless and cost effective design through weekly conference calls and periodic design conferences. Engineering services included providing: final routing of duct bank, a complete set of plans and profiles, pulling tension calculations, cross bonding calculations, duct bank design, ampacity calculations, and construction support.

• Technical Routing & Layout
  • Detailed Engineering
  • Pulling Calculations
  • Trenchless Crossing
  • Layout
  • Construction Drawings and Specifications
• Construction Support