Performed comprehensive maintenance on a Carrier 48HC rooftop unit at a local office building. Cleaned condenser coils using Nu-Calgon Evap Pow'r-C. Replaced clogged air filters with MERV 13 pleated filters. Inspected and tightened electrical connections with Klein Tools torque screwdriver. Lubricated fan motors using Supco synthetic lubricant. Checked refrigerant charge with Fieldpiece SMAN460 digital manifold. Calibrated Honeywell T6 Pro thermostat for optimal performance.