Doubt in powering pcb's

Hi,
My powering plan of pcb's is given below..



The current consumed by a PCB is 1 A. The tracks in the pcb which carries power can capable of carrying 5 A. Two voltage sources of current rating 5A is used to power 3 pcb's each.

Since i need to communicate across these 6 pcb's the grounds should be common. So i can connect the ground of pcb 3 and 4 by using connector which carries only ground line and not the positive line.

But my doubt is if i use the same connector which carries positive and ground lines as other connectors to connect the pcb's 3 and 4, will it be any issue?

Specifically, since the total current taken by the system is 6 A, if i use the connector which carries positive and negative lines to connect pcb's 3 and 4, will the entire 6 A flows through the power tracks of all pcb's? (OR)
will 3A flows through pcb's 1,2,3 from Voltage source 1 and remaining 3 A flows through pcb's 4,5,6 from voltage source 2?

Thanks,
Murugesh

What happens when one of the PSUs fails or goes low in voltage. The other one will attempt to take the load.
Frank

Also if anyone PSU shorted, will the entire system collapses?

You cannot parallel up power supplies unless they are specifically designed to do that (usually they aren't). They won't share the load equally and you could end up with one power supply feeding power into the other.

Simply connect all grounds but don't link power between PCBs 3&4.

Keith

If PSU 2 get shorted between its positive and negative, will it affect the pcb's under PSU 1 or they will work?

If your power is routed as in your diagram, a short on PSU 2 will also short PSU 1. If you only bridge the grounds of boards 3 & 4 then a short on PSU 2 will leave boards 1 to 3 still working.

Keith