Two floors of this seven-story building were undergoing major renovation to be ready for permanent shelter housing, with the remaining floors planned as future offices for county government agencies. That meant the 50-year-old rooftop generator needed to be replaced, to provide the building with reliable emergency backup power.
Electrical contractor America’s Best Service, Inc. (ABS) of Crofton, Md., took the project from the top, installing a new generator, a 350KW MTU natural gas unit, on the roof of 2020 North Courthouse Road.
To start the project, ABS provided full engineering and stamped drawings of the generator project, including a structural study to validate the existing roof conditions.
One challenge was the gas pressure, said Service Operations Manager Eric Jones. Because the new unit is more powerful than the old one yet still sits on the roof, it needed an upgraded gas meter and line system to bring up enough pressure from the basement. “We worked closely with the power and gas companies to ensure the new unit would operate correctly,” said Jones. “After calculating the energy needs and pressure requirements, we coordinated with the utilities to upgrade the lines.”
ABS also built a new electrical room to house the required switch gear that interlocks the emergency connection points and installed new transfer switches, panels, conduits, feeders, and controls. The project required numerous electrical outages to complete the final connections.
A two-hour rating was required for the emergency feeders, and ABS provided all the needed building-related work to support them. ABS obtained all county permits and inspections required and provided start up, load bank testing, and training on the new unit.
“Ultimately, the county received a fully installed, ready-to-go generator with enough panel space to carry its projected loads,” said Jones. “And while this work was done under rigorous time constraints, it was completed on time—and within budget.”