SEN0211 Sketch example math calculation

Hi,

I have SEN0211 and have been trying to understand the sketch maths for calculating the current.
Getting the average analog pin value then the RMS voltage is fine so then we have:

voltagevirutalvalue * vref/1024

So this is to calculate the incremental voltage per bit resolution given it's a 10bit input on the Arduino (my UNO is) a 5v supply and then we divide by two as it is AC.

Ok, so firstly why is vref 5500 not 5 and secondly, why is the voltage not proportional to the
output voltage of the module which is 0.2 to 2.8 volts based on a 0-1v input on the 20Aclamp.

Or am i missing something?

J

ACCurrtntValue = voltageVirtualValue * ACTectionRange;