Expert-level knowledge of critical electrical systems, including transformers, switchgear, generators, automatic transfer switches (ATS), static transfer switches (STS), power distribution units (PDUs), static UPS systems, and 480/277V and 208/120V electrical distribution. • Expert-level knowledge of mechanical systems, including chilled water systems, large centrifugal chillers, cooling towers, heat exchangers, water treatment systems, variable frequency drives (VFDs), pumps, HVAC equipment, CRAC/CRAH units, and humidification systems.