Firstly, I am a ME seeking advice from EE's. I have a Quadvolt voltage data acquisition box from Omega (P/N: OM-CP-QUADVOLT-30V) http://www.omega.com/pptst/OM-CP-QUADVOLT.html, that I intend on using to monitor current through a 100A 50mV current shunt in a 12 volt solar system that powers a light.
I want to monitor current in the positive conductor between the battery and the solar/light controller. My problem is that the Omega box cannot handle reverse polarity. I am concerned that when the system switches from charging to drawing power from the battery, the current direction will switch and therefore (I would assume) the polarity at the current shunt would switch, correct?
If my logic is correct I want to be able to protect the Omega box. I had landed on using an N-Channel MOSFET in series with the negative side conductor from the current shunt to the Omega box. Then I got lost in all the terminology. Since the voltages I am monitoring are so low, on the order of 50mV, will a MOSFET protect the box without causing noticeable voltage drop? Will negative 9-13 volts be enough to actuate the switching device and protect the Omega box in a reverse polarity situation?
Found this recommended on another page https://www.digikey.com/product-detail/en/SI4838DY-T1-E3TR-ND/SI4838DY-T1-E3TR-ND/1656477. Would this work for my application? Thanks so much for the help! I'm lost when it comes to this stuff!