Perform fabrication, installation, alteration, troubleshooting, repair, operation, maintenance, adjustment and monitoring of a variety of air conditioning systems including large commercial and industrial chiller units and other associated HVAC/R components such as compressors, motors, variable air-volume, air handling units, ductwork, control systems (pneumatic, digital, and electronic) and equipment safety devices. Repair and/or replace pneumatic control lines and valves relating to pressure reducing stations, radiators, heating and cooling coil control valves, unit heaters, boiler control, and thermostatic controls.