Relay Data Sheet question
Coil current and voltage are what the signal side of the relay need in order to actuate the mechanical switch on the other side, which is called the contact. So you need to give the relay 4.5mA at 33.6+ VDC (maximum required voltage to switch) and it will switch up to 6A at 400VAC. I believe that the 2.4 VDC is the minimum point at which the coil will release the contact - that is, your low level must be less than 2.4 VDC.