As you may have read in a previous post – Need More Power – we added a pretty cool system to simplify our power usage on Jade Panama’ and give us some pretty nice benefits. However, there was one area that still needed to be addressed. Our boat has only a 50a / 240v plug in / input. So, we either are on a dock with 50a/240v service, or even potentially two 30a of opposite phase, or run our gen.
Frequently in the PNW when we get to a dock without 50a/240v power, they will have multiple 30 120v plugs which when on the opposite phase can be combined with a smart combiner to create a 30a/240v power supply. This works well with our system as we can just tell the Victron Quattro that we only have a 30a supply and it will limit power draw to that and supplement any addition power need by the Assist mode and pull from the batteries.
However… and this is the gotcha, there are three other scenarios that are unfortunately more common that we would like. They are docks where there is only a single 30a feed, docks where there are multiple 30a feeds but are fed from a 3 phase supply which results in a large voltage drop when combined, and lately the new ELCI power where you cant use the smart combiner to simulate a 240v supply as they will just trip the breakers.
So, what do we do to account for the above?? Well, what I did is we added a 30 power input plug to Jade Panama. We run this 30a/120v input into a Victron Autotransformer which has the ability to step up the voltage from 120v to 240v. When you do this your amperage is obviously cut in half so now a 30a 120v input becomes a 15a 240v supply, but because of capabilities of our Quattro, this works quite well. Remember from the previous article, the Quattro can do current limiting, and when additional current is needed above and beyond the supply, it will assist from the battery bank. We just set the current limit to 15a, and while 15a/240v is not a huge supply, on average it tends to do just fine. When the AC or Heat is not on, the draw is less and it will be recharging the bank… when those systems are turned on, it goes into assist mode.
We tested this a few weeks ago in Poulsbo which has the ELCI power, and ran for 3 days using a good amount of Heat (reverse AC), and we were able to function quite normally with the Quattro charging and assisting as necessary on a single 30a/120v circuit. It worked flawlessly.
To complete the install, I put another AC selector switch by this new AutoTransformer which selects between the 30a/120v input and the 240v input, and sends that power up to the panel and ultimately to the Quattro. This ended up being a very simple yet elegant solution to our need.
One additional note – the dock crew at Poulsbo mentioned that if we had a non smart Y combiner (take 2 – 30a/120v leads and combined them to a 30a/240v of opposite phases) that this will allow you to use both legs without tripping the breakers. Its the smart functionality in the combiners that causes issues. I have not tried this yet but may test it out in a future visit. Note – you would want to take care to be sure you were on opposite phases for true 240v applications.