The electric power is distributed using a tri-phased grid.
In such a configuration, we distinguish two voltages:
| - | The voltage between two phases Vpp, |
| - | The voltage between phase and neutral conductors Vpn, which is the usual connection for the distribution in the house for most domestic appliances. |
The ratio between them is the square root of 3: Vpp = sqr(3) * Vpn.
In European countries, the normalised low voltage in households is:
| Vpn = 230 V +6% / -10% (i.e. ranging from 207 to 244V) |
| i.e. | Vpp = 400 V +6% / -10% (i.e. ranging from 360 to 424V) |
In the US zone, there are several standards:
| Vpn = 120 V (no more very usual) |
| i.e. | Vpp = 208 V (some homes wired between 2 phases ?) |
| or | Vpn = 236 V (or 240 ? - Which range ?) |
| i.e. | Vpp = 408 V (or 416 ? - Which range ?) |
NB: Sorry, we don't have precise information about the situation in other regions.
