PLM has specified and designed many substation, transmission line and distribution projects. We have experience in both turnkey EPC projects and traditional Design - Bid - Build projects. We are recognized for providing a well thought out, cost effective design that meets all client requirements. Our detailed design package often results in limited or no contractor change orders during the construction process.
A typical design project starts with a detailed Design Memorandum that sets forth the basic criteria that will be used to design the facility. Following client review and approval of the Design Memorandum the conceptual project design and and schedule are prepared, followed by any required permitting activities, specification and bidding of major equipment, and preparation of the construction contract. In most cases we provide construction phase services, including review of contractor submittals, field review of the work progress, assistance with utility interconnection requirements and preparation of relay settings. A final as-constructed drawing and record package is prepared at the close of the project.
The Middleborough Gas & Electric Department contracted with PLM to provide engineering and design services for a new 3.75 mile 115kV overhead transmission circuit. The project established a second 115kV delivery point to enhance customer service and address rapidly growing load levels.
Municipal Substation & Distribution Conversions
The Town of Wolfboro Electric Department's distribution system was operating entirely at 4.16kV and the Town was relying on expensive on-site diesel generation to relieve its fully loaded substation facilities during peak load periods. PLM began with a System Planning Study to address thermal overloads, low voltage, inadequate reactive support and other unacceptable conditions. Based on the Study recommendations, PLM prepared design and contract documents for the construction of a new open bus 34.5kV to 12.5kV substation. The project also included preparing design and contract documents for the rebuilding and conversion of a major portion of the 4.16kV distribution system to 12.47 kV operation.
GIS Indoor 115kV Switchgear
The Norwood Municipal Light Department needed to construct a second 115 to 13.8 kV substation. After a comprehensive system planning study and much community input, it was decided that an indoor substation utilizing 115kV GIS equipment was the design of choice. PLM assisted with permitting at the Massachusetts Energy Facilities Siting Board in order to obtain permission to construct a 2.2 mile underground extension of the 115 kV system. PLM prepared design and contract documents for the 115 kV GIS switchgear and all other major substation equipment, underground ducts and manholes along busy US Route 1 and 115 kV underground cable turnkey installation.
This "design-build" project had an extremely aggressive schedule. The PLM engineers coordinated the design and schedule with the constructor, the upstream utility, the project owner and the owner's independent engineer. The substation was completed on time and within budget. The project received a nationally recognized award for "outstanding engineering and operations design."