Completed preventive maintenance on a 5-ton Carrier Infinity system with variable-speed compressor. Inspected contactors for pitting, measured capacitor microfarads (within 6% of rating), and verified refrigerant pressures (410A at 125/425 psi). Cleaned condenser coils with enzymatic cleaner, removing significant pollen buildup. Checked superheat (12°F) and subcooling (11°F) - both optimal. Calibrated TXV and verified proper delta-T across evaporator. Customer's system is now running at peak efficiency.