37 MAINTENANCE OF ELECTROTECHNICAL EQUIPMENT INSTALLATIONS; CONSTRUCTION, INSTALLATION, REPAIR AND MAINTENANCE FOR TECHNICAL SYSTEMS, NAMELY, ELECTROTECHNICAL SYSTEMS AND EQUIPMENT USED IN INDUSTRIAL OPERATIONS, NAMELY, COMPUTER HARDWARE, CIRCUIT BOARDS, ELECTRIC SWITCHES, AND INDUSTRIAL MACHINERY; RENOVATING USED INDUSTRIAL PLANTS FOR NEW OPERATIONS; CONSTRUCTION PLANNING OF INDUSTRIAL PLANTS FOR OTHERS