Autotransformers are used when galvanic isolation from the supply network (i.e. between the input and output windings) can be dispensed with. In this case, the input and output windings are electrically connected. A distinction is made here between throughput power and construction power, whereby the construction power is always lower than the throughput power. The lower the difference between the input and output voltage, the lower the power rating.

The corresponding standard for autotransformers is EN 61558-2-13.

Type power = (1 – undervoltage/overvoltage) * rated power

Please observe our instructions for the use of three-phase autotransformers!