Demonstrated ability to understand and apply operating principles, intended functions, proper applications, and design limitations of electrical, pneumatic, and mechanical systems, including steam and electric chillers, compressors, cooling towers, pumps, AHU and MUA units, fans, thermostats, humidistats, heat exchangers, and condensate pumps. Proficient in performing preventive maintenance (PMs) on steam and electric chillers, cooling towers, rooftop units, and AHU and MUA system, and ability to identify appropriate replacement parts or suitable substitute components to ensure reliable system performance.