We are designing automation of our electrical panels and to read current we have gotten couple of Allegro ACS758 hall effect current sensors. According to the datasheet and search on the web alongwith user reviews this device produces 2.5 V DC output at NO LOAD and increments the voltage by 40 mV / 1 A. We are using this to measure AC current and we have tried couple of the devices and gotten same results. We passing 6 A of current through the IP+ and IP- terminals but we our DC voltage out is still 2.50 V and not even bulging even by a mV. Even though it is AC if IP+ and IP- terminals are reversed we should see lower voltage but it is not. We even tried changing the polarity of these terminals but no avail. We are using the capacitors as suggested in the datasheet. We have seen some reviews online and users are seeing the change in DC out based on current being pulled but we are not. I could imagine if one of them could be bad but we have tried 3 of them and all are giving same results.
Please help if anyone knows what is going on.