This is a fire pump.
It pressurizes your sprinkler system when a sprinkler head goes off. Power to this pump is supplied from the standby generator when the fire department turns the power off during a fire. The generator must work. International Fire Code says the generator/fire pump system must be tested together under full load annually.
See NFPA 25.
You do not want to lose your sprinklers during a fire!
Test the system.