Max 4HD dual power 12vdc and 24vdc

Can I use dual power via the terminal blocks? 12vdc on one and 24vdc on the other. This will assure i always have power even during 12 volts battery bank switch overs as the we cannot switch between banks on the 12vdc and 24vdc systems at the same time.

Yes you can. The HD series is quite agile when it comes to variable voltages.

Arent the DC block’s hard wired? If you apply 12v on one and 24v on the other simultaneously this will give you smoke…

You’re right. To be clear. Only one voltage can be presented to the green HD4 terminal block.
You can supply different voltages to the green terminal block and the black 2.1mm DC barrel inputs though quite happily.

That would great info on the manual. Also, does hard wiring two block to the same system open the router to ground loop a potential issues as power would coming from discrete power sources?