Maintenance and operation of electrical power generators, high pressure transformers, switches, operating boards, circuit breakers, distribution system panels (high/ low voltages), control room, indoor and outdoor lighting system, illumination control system, elevators, escalators, furniture conveyor system, automated electrical doors, Building Management System (BMS), Unending Power System (UPS), Automatic Telephone Switching System (PABX), Closed Circles Of Television System (CCTV), Master Antenna Television (MATV), Fire Alarm System, Public Address System, and cameras for observation and others.