Inverter setup / installation
Our inverter needs are fairly simple when it comes to the amount of power we need. We don’t run a coffee maker, TV, fridge or any other high draw items. We do want to charge the batteries on all of our cameras, computers & electronics which we do have a fair amount of. In our old camper we had an inverter that plugged into a 12V power outlet – the outlets that look like the old cigarette lighter thingies that cars use to have. That was a bit inconvenient and only allowed 1 or 2 things to be used or charged at a time.
So the plan was ambitious, and that was to make all the outlets in the trailer live when our 400 watt inverter was on. That was more complicated than you would think… some of the work tied in nicely with the built in generator install. The generator, the 12V batteries and the inverter all live in the front bay, so a 30-amp power cord had to be pulled through the trailer’s underbelly to the transfer switch and electrical box at the very back of the trailer. While pulling this cable I also ran another 16-gauge 12V cable to the rear electrical box (more on that later). The generator and the inverter go through another transfer switch in the front compartment, and an 120V cable is plugged into both the inverter and generator. The transfer switch defaults to the inverter, if the generator comes on the inverter is automatically disconnected. Now at this point the whole trailer’s 120V circuits are connected to the inverter.
You’d think we were done at that point, but no there are some serious problems with plugging the trailer directly into the inverter. Obviously the high draw items like the air conditioning and microwave can’t be run, but it’s easy to just not use them. The fridge’s 120V circuit draws about 300 watts and does run off the inverter – which is a great way to drain the batteries quickly, so the fridge gets switched to propane. No problem there either. That leaves the built in power converter / battery charger, trying to run off the inverter. Imagine the batteries trying to charge themselves in a vicious loop. It doesn’t work, the protection circuit on the inverter is immediately triggered and it shuts down. In testing the whole system out I found that if I manually turned off the breaker for the power converter / battery charger everything would work. The 16 gauge cable I pulled back earlier supplies a signal to a relay (12V coil and 120V 40A contacts) that controls the power to the power converter / battery charger. When the inverter is switched on 12V power is supplied to this relay deactivating the power converter / battery charger.
TO DO add pictures to post.
PICS needed:
Inverter
transfer switch
trailer rear electrical panel & relay
inverter switch
30 amp wire
pics of wiring layout for inverter / genset.
