If you are in the US why did you buy a 230v inverter/charger? Is that why you have the transformer?
just trying to wrap my head around that
Our off grid cabin Victron/Trophy setup
- Thread starter barthold
- Start date
just trying to wrap my head around that
I have 240V and 120V loads. So I need both voltages. There's two ways to do that. 1) With two 120V inverters working together (which you can do with Victron inverters), or with a single 240V inverter and an autotransformer. Think of the 240V (well really 230V but that is not important) inverter as having two 120V outputs (which is has) but what is missing is the neutral to reference those 120V outputs to. The autotransformer will create that neutral for you. So the output of the autotransformer is two 120V legs, and a neutral, and now you have all you need to feed either 240V loads (use the two 120V legs) or 120V loads (use one or the other leg, and the neutral).
The main advantage of an autotransformer and a single inverter over two inverters is that you can pull the full load of the inverter over one leg at 120V. Say if you want to build a 6KW system, you can get two 3KW 120V inverters, or a single 6KW 230V inverter. With the two inverter option, you cannot draw more than 3KW on a 120V leg, as the inverter can't handle more. With the single inverter, you can draw the whole 6KW on a single 120V leg through the autotransformer.
but if you drew the full 6kw on the single leg that’s it. With 2 inverters you pull 3kw off each leg and you still end up with 6kw.
(Not questioning your process, I’m learning and curious)
I haven’t picked my voltage, or even what brands but trophy and Victron are on the short list.
dan at trophy has been helpfull. He even apologized for not responding back to me sooner (it was like a few hours, lol). Very very helpful.
I really like the Victron “system” and that with the distribution stuff makes,for,a really nice looking clean instal. (Wife would be irked by a bunch of,cable and busbars).
add all the fancy connections, monitoring, wifi, etc and their suppport and we have a winner.
After ver 1 & 2...my upgrade in process is all Victron + Throphy added to my current battery bank. If you would like system info I would be happy to provide it. Using plenty of wire duct to keep wires and cables hidden and protected.
I noticed you connected battery negative to ground. Morningstar, and samlex say to do this also.
where does your ac and dc grounds connect together, and where is the main ground connection to earth? (Looking at your overall picture)
your array, all metal bonded together? Seperate grounding rod, or does ground connect with main ground back in your power room?
loghtning protection, spd’s. I didnt see any?why/why not?
That is correct, but if you need 4KW on one leg, you still get to draw 2KW on the other leg with the autotransformer. With the two inverter setup, you do not have that flexibility. So IMHO the autotransformer setup is superior.
Fascinating. So with this transformer I could buy victron’s AIO unit (230v) and “convert“ it to 120 to use?
is it hard to set up? How much power does it use at idle?
You need a DC ground wire, and use the appropriate AWG (mine is 2/0), in case any component on the DC side shorts out. Because such a short from DC positive to ground will create huge amounts of current. If there's no nice thick ground wire to take that current back to the battery, it will find a way, and it will likely find a way through your AC ground wires, which will subsequently melt due to the high current.
AC and DC ground connect together in the inverter.
The main ground connection to earth is in the standard 110/220 electrical panel. That is also where neutral and ground are permanently bonded on the AC side (I do not bond it using the autotransformer, as there's no need to "unbond" in a fixed setup like this. In a RV or boat setup there is such a need)
All my solar array poles have separate grounding rods right next to the pole, as per electrical code.
As for lightning protection, that is a huge topic. So I'll keep it really short. In essence, as long as the grounding is solid, I am not too worried. The main thing here is to make sure that ALL wiring coming into your house comes in at the same point physically, so you can ground all those wires to the same ground system right there outside your house (telephone, cable, solar, DirecTV etc all grounded to the same ground rod(s)). If you do that, then a close lightning strike cannot create a voltage differential across your ground wires, which is exactly what you want to prevent. A voltage differential over ground wiring is what kills electronics.
If you want to build something that can withstand a direct (not a near) lightning strike, you're looking at something else.
Hope that helps!
BTW in case of doubt, do hire a good electrician or solar installer. This is not stuff to get wrong.
Yes!, Plus you can also use the 230V output to directly feed any 230V loads. The Victron "european" 230V inverter can be set to produce 60Hz, instead of 50Hz, and off you go!
Download the Victron autotransformer manual and read that one. It has good info in it. Also read this article on how/why an autotransformer (it is on a boat, but that doesn't matter, other than the ground to neutral bonding which we can talk about separately).
When you say "AIO" what unit do you have in mind? Make sure the manual says it can be set to 60 Hz. I know the Multiplus II charger/inverter can.
Do you have a generator? If you go this route, your generator needs to produce 230V as well. A 110V generator cannot be hooked up to the 230V Victron inverters.
so your equipment ground is all connect to the busbar > ac/dc combines at the inverter > then into,ac service panel > into the earth
ac system is bonded to neutral in panel
dc system is bonded from battery negative to busbar
is that right?
as for your ground rod at the array is it connected to the rod at your house/cabin?
looking at filter guys grounding downloads it shows to have on;y one ground rod. The solar panels are bonded together, and then the ground is sent to the main ground rod.
just wondering how, and why you did it your way?
I’m looking at the Victron “easy solar”
I really just need an AIO unit, but the ones everyone use (here) scare me. Poor instructions, and I’m not reading good things about so,e of the dealers.
easy solar would be perfect, but it’s 230, not 120.
The battery bank is currently grounded. In the upgrade it will not be grounded as per battery manufacturer.
So, there will be no AC/DC grounds together in the upgrade.
My AC ground system is at the house utility room right next to the equipment. It consists of 3 x 8' ground rods (10' apart, 7.5' deep) bonded with 6AWG bare copper buried 12" deep. That system also is the ground for 1 array's surge protection since the PVs are on top of the utility room roof. The other 2 arrays share a common earth ground for lightening/surge protection. Again, 3 x 8' ground rods (10' apart, 7.5' deep) bonded with 6AWG bare copper buried 12" deep.
All PVs (each PV separately) are ground connected together via lay-in lugs and 6AWG bare copper, then to the shared earth ground. 1 of the arrays has its 30' of 6AWG bare copper buried 12" deep connecting to the 2nd array's ground where the ground rods are. So that is about 60' total of copper in the ground for the earth grounding.
Each array has a 10ka SPD at the Eco-Worthy exterior combiner box. Inside the utility room, at each array's fused disconnected, is a 20ka Midnite Solar 300vDC surge protector. Those grounds are tied into the AC ground system that is at the house as mentioned earlier.
My main circuit breaker panel has a Midnite Solar 300vAC sure protector.
Correct.
Sorry I had you confused with Barthold. Do you have any postings about your system?
your bank is a trophy battery currently grounded (bonded)?
if (for example) Victron says to bond battery, and battery says not to who do you believe?
I need to double check that. I believe there's a ground wire connecting the two also. Not entirely sure on top of my head actually.
I would want to understand why exactly.
filter guy, Morningstar, samlex and Victron say to bond dc system to ground.
I did watch a webinar from Morningstar yesterday and they talked about bonding dc system. It has to do with their charge controllers, and inverters having common negatives.
so to me anyway the inverter,instructions should supersede battery? I dunno. some of the rack battery’s have a ground connection, but that’s an equipment ground.
Right, it makes sense to bond the DC system to ground. So I want to know why (and which) battery manufacturer says to not do so, and under which circumstances.
