The voltage of the alternating current, appears in abbreviated form as Vca (Volt Alternate Current) or from the English Volt Alternate Current as Vac.
In the nautical sector, it normally corresponds to the power supply provided by the quayside which, via a cable, reaches the 220 Vac magnetothermic switch. But it is also the one provided by the internal combustion engine generators or by the 12 Vdc / 220 Vac inverters, which are often used when the boat is not on the dock and it is necessary to use domestic accessories at 220 Vac.