Power Boost not working? Multiplus 2x120

[bobbiemartin]

The Autoformer and Multiplus do different things. The Autoformer boost voltage, the Multi power assist boost current. Just a quick aside on 50 amp vs 30 amp at the campsite. 50 amp is 240 volts at 50 amps. That’s 2X 50 amps at 120 volts. So actually it’s 100 amps at 120 volts. 30 amps is 120 volts, so less than 1/3 the current of 50 amp shore power. So on 50 amp you will likely never use the power assist feature but on 30 amps, it’s quite likely. If you use a watt-amp-volt calculator, you will find 30 amps@120 volts is about 3600 watts. Reduce the voltage and you have even less. A rooftop AC unit draws about 1200 watts, a coffee maker, toaster, etc may draw about the same. In addition a motor (or AC compressor) starting will draw quite a bit of current when it starts. Soft starts on the AC units will help here. OK, so if you exceed 30 amps with the Multi, the inverter will assist with whatever amps it can. We have a Quattro in our motorhome, slightly different to your setup but essentially the same. We occasionally camp at 30 amp sites and pretty much live as normal, running 2X AC units and various electric devices at the same time with no issues. We don’t have a washer so I can’t comment on how that would work. The inverter switches to assist seamlessly depending on load. Now the Autoformer is very different. It boost voltage, but cannot boost current, in fact it takes a bit of current to increase voltage. So if you exceed 30 amps it will not help. In my opinion, if you had to choose between an Autoformer or power assist inverter, the Multi is much more beneficial than the Autoformer in day to day usage. I just bought a very nice used 30 amp Autoformer for US $40, so you just have to keep looking, they are out there. I have only used it once, so can’t really report on how well it helps. Couple things I might suggest, is the washer on a dedicated circuit? Do you know what size wire is going from the panel to the washer? You could be getting a power drop there, I might be tempted to run a 12 gauge cable from a dedicated 20 amp breaker to the washer if possible. Finally, yes you could run the washer on just the inverter by disconnecting shore power but my guess is you will need a good size battery to run it.