Questions about Powerwalker AVR 3000/SIV Schuko 3000VA / 2400W automatic voltage regulator

Unfortunately, we have not stored this, but the manual could be found here: https://www.manua.ls/powerplus/avr-3000-siv-fr/manual

Unfortunately, I could not find any built-in batteries.

Voltage yes; frequency no

The unit is unusable

not usable for your application i guess, in and output are NOT galvanically isolated. (i measured/tested) its just a transformer with 5 taps that switches automatically to keep the output voltage between 180 and 245V for input voltages between 120 (NOT 110) and 250V input standby use 15-30W (dependent on V-in), probably an auto-transformer, N-in is directly connected to N-out.

The following is stated as the contents of the package: AVR, Manual, Input Cable.

It seems not. According to the manufacturers website: "PowerWalker AVR SIV Series are automatic voltage regulators with selectable input voltage 150-270VAC or wide 110-280VAC. It provides output voltage within allowed limit of +/-10% (207-253VAC) through boost and buck stabilizers."

So lang das die Schwankungen nicht zu hoch sind: Laut Hersteller : "PowerWalker AVR SIV Series are automatic voltage regulators with selectable input voltage 150-270VAC or wide 110-280VAC. It provides output voltage within allowed limit of +/-10% (207-253VAC) through boost and buck stabilizers."