I've added a secondary SmartShunt to my travel trailer system for the purposes of measuring consumption on the DC side of the installation. I am getting odd readings that don't fit intuition.
Question is: when I set the shunt to DC Meter Mode + "Generic Load" or "DC System" I get negative output numbers on the meter, causing Cerbo to show the DC system as a supply to the system (little dots travel from DC System to Battery). Intuition says this 24/12v DC converter should be a load and it certainly is the DC System as every12v circuit is downstream from the Orion 24/12. If I change the mode to DC Meter + "Generic Source", the reading flips from negative to positive and things look correct in Cerbo (dots travel from battery to DC). What are the definitions of a Load, Source and System in this context?
My setup is a 24v battery and inverter system with an Orion DC-DC 24/12 stepdown device to supply 12v for the trailer. I have wired the Orion as the only appliance downstream from the shunt as a 24v device with "stuff" attached to it, I only care how many amps the stuff wants.
Thus:
Trailer ground -> SmartShunt "TO BATTERY MINUS" bolt
SmartShunt "TO SYSTEM MINUS" bolt -> Orion 24/12 stepdown negative post
24v supply from batteries -> SmartShunt 24v input of Orion DC-DC
Orion DC-DC 12v output -> trailer 12v DC fuse panels