BONNEVILLE DAM POWERHOUSE 1 METERING ENHANCEMENT

Project Background. - Bonneville Power Administration (BPA) would like to enter the Energy Imbalance Market (EIM), to do so, BPA needs additional high accuracy class instrument transformers. The requirement for CTs (Current Transformers) to be installed approximately 26 feet above the existing roof elevation, above truss-beam. New mounting supports will also need to be installed for the CTs and pedestals on top of the existing roof.

The structural and electrical design, provided by the Hydro Design Center (HDC), provides supports for the new CTs, station post insulators, and busses at locations that provide the required electrical clearances. The HDC designs also evaluates the requirements of supporting the new CTs, station post insulators and busses on legacy roof structural system. The Government will provide the metering-grade CTs and PTs (Potential Transformers), and three deflection insulators. PT’s will be replaced in existing location.

The Contractor will maintain the maximum distances from ground for each phase to add the real time metering accuracy PT’s and CT’s as directed by the requirements. Project Scope. - BPA has the required metering CTs and PTs in inventory and will provide these to The US Army Corps of Engineers as Government-Furnished Equipment (GFE) for the metering enhancement installation contract.

This eliminates the over one-year lead time for commercial procurement of the CTs and PTs after contract award, which would be an unacceptable delay. Bonneville Project O&M staff have committed to furnishing and installing the low-voltage conduit and wiring to the RTU room in the powerhouse. BPA will design and separately install the new control board in the RTU room and will complete the wiring connections.

This reduces the installation contractor's scope to fabrication and installation of the new CT supporting structures as detailed in the Plans and Specifications, installing the CT's, replacing the PTs on their existing supporting structures, and field acceptance testing of the GFE instrument transformers.