well, RB411 with high power card can be easily fed. it is around 7 to 8 W and with 24V for RB433 with 2 high power cards choose as high as you can get PSU, that RB750UP works and you should be fine with two connected to the router. As Rb433 with 2 R52Hn uses around 14W
Also note that when card works in high rates it uses less power, so cutting down small rates (6Mbps, 9Mbps) can reduce the power consumption of the setup. (That is if clients still can associate with the AP without use of lower rates.
3 high power cards will be too much by any stretch of imagination using around 21W just cards alone. On the other hand board has Fast Ethernet ports (100Mps) why would you connect board with 3 802.11n cards to that anyway.
Oh and if you go with R52n cards, you can power quite a plethora of devices and configuration, just that board has 100Mbit interfaces.
It depends if there is a single 2amp power regulator providing power to the ports, or four independant 500ma power regulators providing individual power lines. If you look at the board itself, you should be able to follow the actual traces and see if they all go to the same place, and then see what that regulator is and look up the specs on it.
There IS a regulator somewhere… even if it is just the main regulator providing power to the entire board. Someone with this board needs to follow the traces of the power pins of the ports and see where it goes… that will help determine the actual power limit.
How much current can be used if we use ether1 for powering? I know 2.5A total through the DC power plug but what about using the poe of port 1? Is it the same?
what do you mean power consumption? depends on what you connect there. max power that can be provided is 500mA. maximum voltage - same as RB750UP input voltage.