Performed comprehensive AC maintenance on Carrier 24ABC6 system. Cleaned condenser coils using Nu-Calgon 4291-08 Evap Foam No Rinse. Checked refrigerant charge with Fieldpiece SMAN460 digital manifold, adjusting R-410A levels to manufacturer specifications. Inspected and tightened all electrical connections. Replaced worn contactor with Honeywell DP2030A5004. Lubricated condenser fan motor bearings with Super Lube 21030 synthetic grease. Cleaned evaporator coil and condensate drain line. Replaced air filter with MERV 11 pleated filter. Tested capacitor using Fluke 87V multimeter. Calibrated Ecobee SmartThermostat for optimal performance. System now operating at peak efficiency with 18°F delta T across evaporator coil. Maintenance extends unit lifespan and improves energy efficiency.