I have an electric Power generator and have a manual transfer switch to use a Power generator when the utility power is out. So the electric power generator is used as is with bonded neutral when used stand alone, but must be set to floating neutral when connected to the transfer switch, per the instructions from the manufacturer. I originally installed a switch to the screw on the case, but it is rated to 250V 20 Amps, but my generator has a max of 240V 50 Amps 9KW.
It is difficult to find a small enough switch for 240V 50 amps AC that can fit inside the generator housing. I was thinking if I can use an isolation switch like those used for car batteries that are rated at 500 amps, but at 12 DC Volts.
The transfer switch has the neutrals connected along with ground to the home.