I wrote to Alliance and they told me the box has 12 VDC coming in and 120 VAC going out so it is an easy hook-up. Since this box feeds the 2 TV outlets, two bedside tables (29RL), and one Kitchen outlet it must pass through 120 VAC currently since I don't have an inverter installed.
Looking at the inside of the box (see picture) you will see two black wires and two white wires in Wago terminal blocks. This is the 120VAC coming in and going out. I will have to trace which one actually is the VAC in and which is VAC out. The three wires with the wire nut ties the trailer ground and chassis ground together. Since I don't want those 5 outlets to run off the inverter when hooked to shore power you use an inverter with a transfer switch. The transfer switch will switch between shore power (when connected) and the inverter 120 VAC (when disconnected). The inverter 12 VDC is hooked directly to the batteries through a fuse. Since I am using a 2000W inverter I am using a 250 Amp fuse between the inverter and batteries. To make things really easy, I am purchasing a Renogy 12V Inverter (1000W/2000W/3000W, RIV1210PU-126/RIV1220PU-126/RIV1230PU-126) that has the Transfer switch built in and it has bluetooth so I can use my Renogy BT-2 bluetooth dongle with by inverter and solar charger. Since the Inverter breaker in the trailer is 20 Amps, there is no reason to buy a 3000W inverter. Be sure to follow the instructions since Renogy suggests installing a 20 Amp GFCI plug between the inverter and the select trailer plugs. Remember that this does not power the whole trailer, just 5 selected outlets. If you want the whole trailer powered, leave the inverter box in the front alone and install the inverter and transfer switch to feed the PD4560 Power Control Center (from Progressive Dynamics) located in the trailer. You might need a larger 3000W inverter if you want to start running AC loads.
