An electrician, often referred to as a wirer, is a tradesperson who specializes in electrical wiring of buildings, stationary machines, and related equipment. Electricians may also install or repair telecommunication and electronic components. They are responsible for the installation, maintenance, and repair of electrical systems, including wiring, circuit breakers, transformers, and other electrical services. Electricians must be knowledgeable in the National Electrical Code, which sets standards for the safe installation of electrical wiring and equipment.