Shore-power frequency conversion, in plain language
Ships are built for a frequency. Quays are built for another. A static frequency converter sits between them and synthesizes the shipboard waveform from the quay waveform.
On the Nepson page the machine is sized in kVA (1000 to 4000). Output frequency is 50 Hz, 60 Hz or 400 Hz at 0.01 accuracy. Voltage is listed as customizable, with example currents at 440 V and 6.6 kV.
Two packaging options are printed: a container at IP65 with air-conditioning cooling, and an indoor cabinet at IP32 with forced air.