To connect up your power supply, you'll need some heavy guage wire. I use 12 or 14 guage multi-strand copper wire because this transformer is capable of putting out some serious current.
Connect your power supply to the rectifier and capacitor as shown in the schematic.
There are several sets of wires coming from your transformer, but I suggest using the yellow and red/blk combination so that you'll get around 46 Vdc at the other side of the capacitor. Connect the wires to your rectifier as shown below.
Your capacitor has three terminals on it, but you'll only be using the + and - terminals as shown below.
Before connecting your power supply to the Arcsin board, double check to make sure that the voltage is right around 48 volts. If it is any higher than this, you may need to experiment with a different set of wires on the output side of the transformer to get a lower voltage.