Is it necessary to disconnect zero when connecting a three-phase generator to a single-phase network?
Zero need to be cut off. What is an ARV unit? Maybe ABP? Usually this is done with the help of a cross over switch - with its help they cut off all phases, there are automatic devices - various ABP units. The easiest way to use a cross over switch is to feed all three phases with jumpers from the generator. An example of such a device is ABB OT40F4C. Explain your situation in more detail, what is your block?