The International Electro-technical Commission (IEC),  define low voltage circuits as those with 50 – 1000 Volts for alternating current and at least 120 – 1500 Volts for direct current, and distinguish it from extra low voltage (<50 V AC or < 120 V DC) circuits. This is in the context of building wiring and the safety of electrical apparatus.

Low-voltage consumers are, by definition, those consumers whose loads can be satisfactorily supplied from the low-voltage system in their locality.