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

First of all, it must be specified that single-phase and three-phase concern the electrical circuits in which alternating current flows: both systems, in fact, 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 neutral and one for phase). This is the most widespread system in our homes and is mainly used to power end users such as household appliances and low-power components. The transition from three-phase current (see three-phase power supply) to single-phase current takes place in the electrical substations where the electricity comes out with a single phase and feeds the electrical panel of the house. This type of current is also used for lighting and heating, i.e. when we are faced with low-power users where the savings deriving from three-phase current are practically nil. Furthermore, if we consider that 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 you are wondering which system (single-phase or three-phase) is better, the answer is neither as each is characterized by certain peculiarities that make them more suitable for certain applications rather than others.