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Repair Main Transformers B-1780

Posted in Electrical

This project was awarded to Black Construction Corporation through the competitive bidding process at a total contract amount of $1,199,953.00 with a contract duration of 390 calendar days, 180 calendar days for mobilization and 210 calendar days for site works. Contract was extended due to Super typhoon Pongsona in December 2002. The contract required the upgrade of the Main Power Transformers from the existing two (2) 10.66/16.667 MVA and increased to two (2) 20/25 MVA capacity to serve the entire Andersen Air Force Base (AAFB) electrical distribution system.

The existing electrical main substation is being maintained by two different agencies; the 34.5 KV portion, under the jurisdiction of the Guam Power Authority (GPA), and the 13.8 portion, under the PWC Navy/Raytheon Technical Services Guam (RTSG). Coordination with AAFB, GPA and RTSG was very critical to ensure the various systems and components from GPA, RTSG and BCC s new transformers were properly synchronized to minimize power outages and maintain safety. Construction had to be phased so that one main power transformer could be installed, commissioned and in operation before the second main power transformer could be installed and commissioned.

The Principal work featured in this contract includes the following:

  1. Removal of existing 2 each, 16.677 MVA, 34.5 KV – 13.8/7.96 KV Main Substation Transformer, each transformer weighing 86,380 lbs.
  2. Removal of existing one (1) each Grounding transformer.
  3. Provide, install, test and commission two (2) each new 20/25 MVA, 34.5 KV – 13.8/7.96 KV Substation Transformer, each transformer weighing 110,000 lbs.
  4. Provide and install one (1) each 34.5 KV Grounding transformer.
  5. Provide and install new 15 KV busways connecting new transformers to the existing switchgears.
  6. Provide and install new HV support structures for the new busways.
  7. Construct concrete pad for the new substation transformer capable of 110,000 lbs load.
  8. Provide and install new vehicular gate and chain link fence.

This contract will upgrade the capacity of the electrical distribution system from 16.677 MVA to 25 MVA and will automatically correct low voltages under load to the entire Andersen Air Force Base.

Certificate of Award
Guam Contractors Association 2003 Excellence in Construction Awards
Electrical-Commercial Under $2M-Category Winner