omavahel juhtmetega ühendatud vooluallikas, elektritarvitid, mõõtevahendid ja lülitid, set of interconnected circuit elements, network consisting of a closed loop, giving a return path for the current, Group of elecrical equipment powered from one or more circuits of the electrical installation for one or more zones including one or more services for the purpose of electrical energy efficiency or demand-side power quality.