1) I have a travel travel that I pull with a tow vehicle. I plan to put the Orion-Tr Smart in the trailer, and have it powered with the 12V from the 7-pin connector on the trailer hitch. Do I need a fuse on the input side of the Orion? Or would this be redundant with the fuse for the 7-pin connector in the tow vehicle (presumably 30A)?
2) My batteries are already protected by a circuit breaker (placed near the batteries) that is appropriately sized for the gauge/length of the cable. Would it hurt to have an additional breaker on the output of the Orion? Should this second breaker be sized to the device (18A) or to the cable (which is already protected at 80A at the battery)?