EAC provided services for Building 246, a telecommunications facility, which provides world wide communication support to other DOD facilities.  This building is presently located in a historical district at Fort Belvoir in Virginia.  The building performs extremely sensitive and critical tasks and operates 24 hours a day year around. The main purpose of this project was to improve the reliability of the existing electrical distribution system as well as provide adequate generator back up power for the entire building and uninterruptible power systems for the critical equipment.

Under the proposed work order, EAC designed the replacement of the entire electrical distribution system with a completely new system.  The new system included two exterior pad mounted transformers, each rated at 500 kva, 34.5 kv, 3 phase, 3 wire, delta, primary to 120/208 volt, 3 phase, 4 wire, wye, secondary.  New transformers were provided with oil immersed fuses for the primary (34.5 Kv) side protection.  The transformers are fed from the existing 34.5 kv switch enclosure.  From the secondary side of the transformers, new service cables are provided to the new double ended switchgear, using underground concrete encased ductbank.  
The switchgear is rated at 2000 amp, 120/208 volt, 3 phase, 4 wire with a 2000 amp main circuit breaker.  The main and branch circuit breakers are microprocessor type with ground fault type adjustable trip.  A tie breaker permits power feed from either transformer.  The switchgear is also backed up by two separate 450 kw emergency generators. The critical power is provided via two 130 kva UPS systems.  The switchgear serves two new 1200 amp non-critical power main distribution panels and two 800 amp critical power main distribution panels, via UPS.  New power feeders are provided to the existing branch circuit panels located throughout the building.  For accommodating new electrical equipment, a new addition is also provided.  A new HVAC system is provided to support the new electrical equipment.  Fire alarm system includes new pull stations, audio-visual devices, smoke detectors, and sprinkler system.

Building 246 Fort Belvoir, Virginia