Repairs and opens locks; originates, duplicates, and cuts keys using key-cutting equipment; changes lock combinations; rekeys cylinders; and disassembles locks to repair or replace worn tumblers, springs, pins, and other internal components. Inspects, tests, troubleshoots, repairs, and maintains electrical equipment, lighting systems, switches, outlets, appliances, pumps, valves, fans, window air-conditioning units, Variable Air Volume (VAV) boxes, generators, exhaust fans, and associated building equipment.