Problems getting correct readings from ACS71020
Ok, I've done some testing and i've found out that as stated in the cover of the datasheet the power supply of your ASEK71020KMAB-090B3-I2C and your Micro-controller unit needs to be isolated. You should be able to test this out by powering it all from a laptop using only it's battery (it shouldn't be charging otherwise it wont be isolated).
This fixed my issues with random readings and it should fix yours also. If not you ought to check the code to convert the binary number into a float or integer. In your case your IPr or fullscale current should be 90Amps you should check that out too.
You should also check the &quot;qvo_fine&quot; in register 0x0B/0x1B
As stated in the datasheet page 22


qvo_fine Offset adjustment for the current channel.
This is a signed 9-bit number with an input range of –256 to 255. With a step
size of 64 LSB, this equates to an offset trim range of –16384
to 16320 LSB, which is added to the icodes value. The trim is
implemented as shown in Figure 14. The current channel’s offset
trim should be applied before the gain is trimmed. “qvo_fine” is
further described in Table 1.


In a more definitive project you need to buy a transformer or a ready made isolated power supply that can power all your electronics.