Current consumption of a current transducer (LEM LA 55-P)
Probably not. The datasheet is not very comprehensive so I am guessing a bit. If it's important: measure!

The device itself needs 10mA (continuously) from both supply rails to work. 

And next to that it will draw Is from the supply "in general". If Is flows out of the device it will be drawn from the positive supply (and vv).

So the maximum power drawn will consist of two components: 10mA @ 30V (300mW) and Ismax @ 15V (750mW). Together 1050mW. 

Note that this is the worst case possible, where you continuously measure 50A DC. If you measure sine-shaped (or small) currents, Is will on average be smaller, and so the average power will drop.
In that case you will need to find the rms value of the current you measure to determine the average power you will need for driving Is.