As you may have noticed, browsing our website (especially on the pages of the external units), 2 types of power supplies are mentioned: the single-phase electric current and the three-phase electric current. For non-experts these terms may seem complicated: this is why on this page we have decided to clarify the subject.

First of all it must be pointed out that single-phase and three-phase relate to the electric circuits where alternating current flows: in fact, both systems have an oscillatory pace and the only thing that changes is the number of phases (as the name suggests).

What is a single-phase system?

Single-phase circuits, which are the simplest electrical systems, consist of a single phase (usually 220 V) and have 2 conductors (one for the neutral and one for the phase). This is the most widespread system in our homes and is mainly used to power end users such as appliances and low-power components. The transition from three-phase current (see three-phase power supply) to single-phase current occurs in the electrical substations where the electricity exits with a single phase and feeds the electrical panel of the house. This type of current is also used for lighting and heating, that is when we are faced with low power users where the savings deriving from three-phase current is practically zero. Moreover, if we consider that the single-phase current generally has a lower voltage (220 V), we try to prefer it in residential electrical systems to limit the danger of electric shocks.

Finally, if in the case you are wondering which system (single-phase or three-phase) is better, the answer is neither of the two as each one is characterized by certain peculiarities that make them more suitable for certain applications rather than others.