Well even if the sensor is correctly constructed (and I'm not saying it is or is not) the interface circuitry is just applying a +2.5 bias on which a small AC voltage will be superimposed on that bias. You are then just taking a random one time reading of the voltage with the analogRead() command with no idea where within the 60Hz sine wave you are. You are going to need a much more complex reading method such that you keep reading looking for the highest and lowest values within a 16.666 millsec window so that you can then calculate the RMS voltage that corresponds to the RMS current being drawn from the sensor primary. This is bound to be a very difficult sensing method to make work if at all possible. I would say look for a better AC current monitor that outputs a pure DC measurement voltage.
Lefty