If you look carefully at the picture you posted you'll see the terminations are marked inside. The neutral goes into the far right connection.**** it, if none of yous are going to tell me how to wire it I'll just guess then.
T1 left (T2 centre T3 right - for three phase). The input/supply terminates at the top. Though you need to establish exactly how good your earth is before doing any other work - isn't there an electrician on site!?