Posted by Peter Kennedy on 3/7/2019 to Victron MultiPlus and Quatro
There are a couple of ways to set up a split phase 120/240 volt system using an inverter. The drawing below shows the conventional way where two inverters are paired together in a back to back configuration to work in sync and produce 120/240 volts. This works fine as long as you have inverters that can be ganged together like this to work in sync. The main disadvantage of this arrangement is 1) You need two inverters and 2) You can only draw from inverter one to power leg A and inverter two to power Leg B. If leg B has a lot of load and leg A has none there is no way to get the other inverter to help out, it just sits there.
There is an alternative way of doing this that is more versatile. It uses a 240 volt inverter in combination with an Autotransformer. This is what it looks like.
In this arrangement the Autotransformer can split the 240 volt output of the inverter into two legs and balance the loads between the legs in such a way that you can have all the load on one leg if you want. Its a much better setup with greater functionality and it allows you to use the inverter to its full potential.
All Victron VE Bus Inverters, Multi Plus Inverter Chargers and Quattros are available in 230 volt 50 Hz and with a simple software tweak can be converted over to 240 Volt 60 Hz. They are available for 12,24 or 48 volts DC and in outputs up to 15 KVA. Take a look at our Inverter Charger page for more details. If you dont see a 230 volt version just ask, we dont have them all listed on the site. The Autotransformer is relatively inexpensive and comes in two sizes, 32 Amps and 100 Amps