ESSENTIAL
Mechanic observes pressure and vacuum gauges and adjusts controls to insure proper operation, tests joints and connections for gas leaks, using gauges or soap-and-water solution, wraps pipes in insulation batting and secures them in place with cement or wire bands, replaces defective breaker controls, thermostats, switches, fuses and electrical wiring to repair installed units, may install, repair and service air conditioners, ranging from fifteen to one hundred and fifty tons cooling capacity in warehouses and other large buildings.