I live in an area with unreliable power and also work from home, so I need to keep the home network up without having to go straight to a generator, but that’s what I would use to charge the batteries when the grid goes down.
I’m brand new to this, so I’m trying to smartly start small with a core that can be built out over time.
At first, I’d be more than happy to just have battery backed up 15 amp outlets to run appliances and devices like the cable modem and the rest of the home network.
From there, I’d really like to use that to grow into something that can run critical circuits in the house like the well pump, which is a two-wire 3/4 hp Franklin.
Also, down the road, solar would be nice to add at some point, but it’s not a priority.
So here’s the big question: Where do I start?
I’ve looked at both the Victron Quattro II and the MultiPlus II, but I’m not sure which one is right for me. Heck, I can’t even say for sure that I’m on the right track.
Since I mentioned that my pump is two-wire, I need two legs of 120.
With the two systems mentioned above, how does the Energy Autotransformer fit in?
If anyone has any tips on sizing equipment, I’d be very grateful.
I looked at the inverter-charger product list and I found the Quattro-II 2x 120v, but to my understanding no 230/240v specific model. I’m still trying to figure out the scenario and the product line.
If I did the math right, that would be good to go as long as the pump does not require more than 25 amps to start.
That device will pass through 240V from a 240V grid or 240V generator but does not make 240V as an inverter. It does provide 120V (in phase) to each leg of the split.
It is a pretty big jump from running some internet gear to a system that will run a well pump and other things in your house.
If you are sure you want to end up with a whole-house system and initial cost is not an issue then a pair of Quattros is probably the way to go as it provides separate grid and generator inputs. Also consider the battery bank as that will most likely cost more than the Quattros. The battery bank can usually be expanded later but there will be a minimum size to support the selected inverter but if you can manage the loads connected to it when inverting then a smaller bank could get you started.
To support just the internet gear, then an off the shelf UPS at each location would cost far less. Run time is typically under an hour but should give you ample time to fire up the generator.
I understand that parts of this are awkward, but a large part of the initial project is learning more about how this stuff works. My goal is to make the awkwardness worth it by being able to build on the initial design.
As far as UPSes go, that’s what I’m doing now, and they’re not that great, hence the desire for something more robust.
I guess it all comes down to the end goals but it’s easily a system you can expand on as things go. You just need a defined finish line to achieve this the most economical way
You require split phase 120/240, the ideal setup here would be to use 2 inverters to achieve this over a transformer which is limited in the neutral current it is able to handle
Couple major questions
Grid power is obviously your main source, is generator power an option or something to be considered in the future?
I understand initial goals are just small wattage appliances, what is your end goal (kw/kva)in this setup if you were to power everything you want to from it?
What is your starting budget?
I would say for your desires, if you can swing the initial cost, buy the pair of multiplus or Quattros you need to fulfil your final goals. You don’t have to install them both but having the second unit purchased at the same time will eliminate any potential issues trying to expand the system later on as they need to be of the same hardware revision and identical units to be able to run them parallel/split phase
If you had, say a pair of multiplus 2- 24v 5kva, you could start with a relatively small and cheap battery bank and only utilize the one inverter to handle your modem/router and other little odds and ends. As time goes on and you can afford to expand the battery bank you can start to throw more loads at the single inverter or consider bringing the other inverter online to start taking up the desired 240v loads.
@YkDave, thanks for the advice for two inverters, especially when it comes to neutral current and getting matching models at the same time.
As of now, when the power goes out I immediately break out a generator, even when it’s the middle of the night because my internet connection is also my phone and there’s zero cell coverage here. This is why I’m looking for something that’s a little more robust on the battery side than the small lead-acid UPSes that aren’t enough to cover the typical outage of 4-6 hours.
My initial budget is $5k, so I’m trying to make the most of it.
You mentioned 24v. Is there any particular reason why?
I have no doubt that there’s a reason that’s in my current blindspot.
I mention 24v as it is the cheapest route to start off with if you are trying to start small and expand
Ideally, and especially if you plan on a fairly large system in the end, yes 48v is a better option. But will it fit into your initial budget?
Around here, the 24v victrons are relatively cheap and 12v ~280ah lifepo4 batteries offer the best $/kwh (not comparing them to any other style of battery, but in comparison of other capacity and voltage lifepo4 batteries)
Like I had mentioned before, I’d lean away from 240v inverters and a transformer as your neutral current is limited to 28a which could be an issue later on down the road in expanding the system
Around here a multiplus is about $500 per unit cheaper than a Quattro, so you could save yourself $1k there by going with the multiplus. You can get a $200 auto-transfer switch if you want to hard wire the generator or just keep on doing what you’re doing right now if you need to run it.