About to spend a lot of money tomorrow on this system (am I making a mistake?)

[Hedges]

I don't know much about it, but I am under the impression I will need an auto transformer and that is part of the order I"ll be placing today.

Personal opinion, but "I don't know much about it" should not ever be in the same sentence with "is part of the order I'll be placing today." Best to understand it.

The multiplus puts out 230V, but does it bond one of the two wires carrying 230V to ground? If so you have a bit of a problem. The autotransformer would normally use the two wires of the 230V as two 115V legs, and the center tap of the autotransformer is the neutral. You would normally bond that neutral to ground in your 115V distribution / breaker panel. If one of the two 230V lines is already bonded to ground, you have a problem.

There are a couple other threads on using autotransformer.
Typically for Europe, 2-wire 220V has one wire for "Neutral" bonded to ground. The GroWatt, at least some models, appears to perform that bonding with a relay when grid disconnected, passes through neutral from grid where it is bonded when grid (or generator) connected. We aren't sure that the design allows "Neutral" to be safely driven to 120V if connected to US style 120/240V split-phase (even if internal bonding defeated).

If you have small 120V load, you could use an isolation transformer (not autotransformer) to take in 240V single-phase (one lead grounded), and produce 120/240V split phase. That's two poles of 120V, typical for a house. Transformer only needs to be large enough for those loads.

You could wire the auto transformer without grounding centertap. Then, it would get 240V and neutral from GroWatt, an produce with its centertap a single 120V phase.

Your heat pump likely can run on 240V single-phase, but double check.
Your generator may or may not have output floating so it could connect to 240V with one side grounded. If it does, and if it has 120V outlets on both phases, half of them would have a hot "neutral", which isn't good. If it is only hardwired output, could be OK.

Thanks!

That might take awhile. I don't have anything figured out... But from what I'm gathering the 230V supplied by the Multiplus isn't optimum. Any idea what I would need to do? Step down transformer?

Or perhaps I should go from the Multiplus II to the Quattro II since it apparently can deliver split phase 230V power?

I have no idea what split phase and three phase means. But the Quattro II apparently has "hybrid PowerAssist technology plus multiple system integration features such as three or split phase operation and parallel operation." I would assume split phase would mean I wouldn't need an auto transformer. Whether it makes it easier to split the power into the 110V (which I think it does because it's split phase) or not, I don't know.

3-phase would be three inverters, probably each producing 230V sine waves but each 120 degrees apart in phase. That's for 230V/400V "Y".

I think the Victron units do offer floating output, and Victron has an auto-transformer which will work with them.

 

[AlaskanNoob]

Personal opinion, but "I don't know much about it" should not ever be in the same sentence with "is part of the order I'll be placing today." Best to understand it.

The multiplus puts out 230V, but does it bond one of the two wires carrying 230V to ground? If so you have a bit of a problem. The autotransformer would normally use the two wires of the 230V as two 115V legs, and the center tap of the autotransformer is the neutral. You would normally bond that neutral to ground in your 115V distribution / breaker panel. If one of the two 230V lines is already bonded to ground, you have a problem.

I'm going to pass this on to Victron to see what they have to say and will post the response here. Many thanks!

 

[Horsefly]

r perhaps I should go from the Multiplus II to the Quattro II since it apparently can deliver split phase 230V power?

I don't know everything about Victron, but I thought the Quattro's (and maybe the Multiplus II?) can support split phase, but it requires 2 units, i.e. you would have to have two Quattro's to get split phase. With the Quattro, I think you end up spending extra for the automagic handling of two separate input A/C sources, and you will only have the generator, so that would be wasted $$.

 

[Hedges]

SMA is another premium brand to consider.

It would be nice to have all sealed electronics, but for now their US model Sunny Island battery inverters have a breaker and SD card on the front. New European model is sealed. All these and their Sunny Boy PV inverters use "OptiCool" which means fans over heatsink. They say it is NEMA 3R (rainproof) not 4X (sealed), but all except the fans are in a gasket sealed compartment (not counting the model with breaker and SD card penetrating cover.)

SMA should work well starting and managing a generator. PV can be AC coupled with their Sunny Boy, or DC coupled using Midnight Classic SCC.

22kW of PV you said. 2x SI-6048US and 4x 6kW Sunny Boy could work with that, although battery charging would be limited to 220A from Sunny Boy (more with Midnight, but not able to regulate current). With 4x SI-6048 it would do up to 440A from Sunny Boy. Battery charge current from AC coupled Sunny Boy can be regulated to a desired rate.

 

[AlaskanNoob]

SMA is another premium brand to consider.

It would be nice to have all sealed electronics, but for now their US model Sunny Island battery inverters have a breaker and SD card on the front. New European model is sealed. All these and their Sunny Boy PV inverters use "OptiCool" which means fans over heatsink. They say it is NEMA 3R (rainproof) not 4X (sealed), but all except the fans are in a gasket sealed compartment (not counting the model with breaker and SD card penetrating cover.)

SMA should work well starting and managing a generator. PV can be AC coupled with their Sunny Boy, or DC coupled using Midnight Classic SCC.

22kW of PV you said. 2x SI-6048US and 4x 6kW Sunny Boy could work with that, although battery charging would be limited to 220A from Sunny Boy (more with Midnight, but not able to regulate current). With 4x SI-6048 it would do up to 440A from Sunny Boy. Battery charge current from AC coupled Sunny Boy can be regulated to a desired rate.

I might consider other inverters if somebody can point out that what I have selected won't work and why. Hopefully dealers trying to sell other equipment won't jump in here to confuse me even more while I try to figure this stuff out!

 

[Hedges]

Systems work best if BMS communicates with inverters/chargers. However, some systems are built without that.
Look into what BMS of your preferred battery is compatible with.

 

[AlaskanNoob]

Systems work best if BMS communicates with inverters/chargers. However, some systems are built without that.
Look into what BMS of your preferred battery is compatible with.

The Pylontech US5000 communicates with the Victron equipment. Both companies list each other as compatible.

 

[John Frum]

Thanks!

That might take awhile. I don't have anything figured out... But from what I'm gathering the 230V supplied by the Multiplus isn't optimum. Any idea what I would need to do? Step down transformer?

Or perhaps I should go from the Multiplus II to the Quattro II since it apparently can deliver split phase 230V power?

I have no idea what split phase and three phase means. But the Quattro II apparently has "hybrid PowerAssist technology plus multiple system integration features such as three or split phase operation and parallel operation." I would assume split phase would mean I wouldn't need an auto transformer. Whether it makes it easier to split the power into the 110V (which I think it does because it's split phase) or not, I don't know.

Let me think about it.
For now my best idea is...
I think you should run split phase 120/240VAC to each building.
That way you can use normal setup with a normal ac panels at all the locations.
That means split phase inverter(s).

I also encourage you to look at

1/0,1/0,1/0 & #2 Notre Dame Aluminum Quadruplex URD Direct Burial Cable

600V Underground Distribution Cable. Sold by the foot.

www.wireandcableyourway.com

or

1/0,1/0 & 1/0 Bergen Aluminum Triplex URD Direct Burial Cable

600V Underground Distribution Cable. Sold by the foot.

www.wireandcableyourway.com

Add some fudge factor to the length so you don't end up short.
Its going to be much cheaper than running copper thhn and xhhw even without considering the conduit.
If you are worried about the squirrels it might be ok to just run vertical conduit to a depth below the depth that they are likely to dig.
Anyone know of a good reason not to run aluminum for this application?

I'm not an electrician and I've not read the regs but if I guess its ok and simple to run quadruplex and have a single neutral ground bond at the master panel and the outbuildings will have sub panels without neutral ground bond.

I might run quad wire just in case.

This also means you can run a north american version of that generator.

 

[AlaskanNoob]

I appreciate all the inputs.

So at this point my monkey brai

Let me think about it.
For now my best idea is...
I think you should run split phase 120/240VAC to each building.
That way you can use normal setup with a normal ac panels at all the locations.
That means split phase inverter(s).

I also encourage you to look at

1/0,1/0,1/0 & #2 Notre Dame Aluminum Quadruplex URD Direct Burial Cable

600V Underground Distribution Cable. Sold by the foot.

www.wireandcableyourway.com

or

1/0,1/0 & 1/0 Bergen Aluminum Triplex URD Direct Burial Cable

600V Underground Distribution Cable. Sold by the foot.

www.wireandcableyourway.com

Add some fudge factor to the length so you don't end up short.
Its going to be much cheaper than running copper thhn and xhhw even without considering the conduit.
If you are worried about the squirrels it might be ok to just run vertical conduit to a depth below the depth that they are likely to dig.
Anyone know of a good reason not to run aluminum for this application?

I'm not an electrician and I've not read the regs but if I guess its ok and simple to run quadruplex and have a single neutral ground bond at the master panel and the outbuildings will have sub panels without neutral ground bond.

I might run quad wire just in case.

Thank you, I appreciate it. Hopefully Victron will weigh in today on whether I should keep the Multiplus II or switch to the Quattro II and what is required to make this happen. My monkey brain thinks inverter + wire = power at end of wire. But that's because I have a monkey brain.

I'm not actually worried about the squirrels. They're not going to dig ten feet down for sure, and anything even close to exposed will be wrapped in metal to keep them from getting to it. Just like our cabin's metal siding. I'm not letting them get anywhere near wires out here.

 

[noenegdod]

Thanks!

That might take awhile. I don't have anything figured out... But from what I'm gathering the 230V supplied by the Multiplus isn't optimum. Any idea what I would need to do? Step down transformer?

Or perhaps I should go from the Multiplus II to the Quattro II since it apparently can deliver split phase 230V power?

I have no idea what split phase and three phase means. But the Quattro II apparently has "hybrid PowerAssist technology plus multiple system integration features such as three or split phase operation and parallel operation." I would assume split phase would mean I wouldn't need an auto transformer. Whether it makes it Get

I know nothing about the multiplus II. Get the specs for your heat pump and find out for sure what you are buying and what is requires. If your in NA then it should be 230V split phase. If that is the case, then you do not need a transformer and you do not want a 230V inverter that provides 230v on a single line.

Have a look at this for an explanation of the difference: https://www.bluesea.com/support/art...ope is,the power distribution panel structure.

 

[Horsefly]

I don't even remember why, but I always thought that using Aluminum wire was a bad idea. It may have been the galvanic issues where the wire ties to terminals, or something else. I know we considered Aluminum wire to go from our cabin out to our well pump, and quickly eliminated it as a choice.

 

[John Frum]

n is thinking the Multiplus II can supply 230V across a 500 foot wire where my GSHP will use it

Can you re-state?
I can't parse this.

 

[Horsefly]

I don't even remember why, but I always thought that using Aluminum wire was a bad idea. It may have been the galvanic issues where the wire ties to terminals, or something else. I know we considered Aluminum wire to go from our cabin out to our well pump, and quickly eliminated it as a choice.

Since this got a sad face response from @smoothJoey, and I personally hate to make him sad, I want to emphasize that I really don't know. My comment was to encourage the OP to look into it.

Please don't be sad smoothJoey.

 

[sunshine_eggo]

I appreciate all the inputs.

So at this point my monkey brai

Thank you, I appreciate it. Hopefully Victron will weigh in today on whether I should keep the Multiplus II or switch to the Quattro II and what is required to make this happen. My monkey brain thinks inverter + wire = power at end of wire. But that's because I have a monkey brain.

The primary reason to get a Quattro vs. Multiplus is because the Quattro has two AC inputs vs. one.

There are some combinations of battery voltage/power that are not common to both, particularly for 120VAC units. I have a Quattro because the MP didn't come in 48V/5000W/120VAC.

Quattro and MP are otherwise essentially identical when comparing units of the same battery voltage, power output and AC voltage output.

Another reason to consider NOT using Victron is a UL listing. I'm not aware of any Victron products that are UL listed for use in a residential power system in the U.S.

You will need an autotransformer at each cabin to get 120V.

 

[sunshine_eggo]

Thanks for bringing this up. What do you mean by "92% of your available power?" Do you mean 92% of the power the MultiPlus can supply?

Yes.

 

[sunshine_eggo]

Thanks!

That might take awhile. I don't have anything figured out... But from what I'm gathering the 230V supplied by the Multiplus isn't optimum. Any idea what I would need to do? Step down transformer?

Or perhaps I should go from the Multiplus II to the Quattro II since it apparently can deliver split phase 230V power?

No. It can't. It simply has two AC outputs that are the same 230VAC/50Hz.

No Victron inverter offers 120/240VAC split phase output.

 

[noenegdod]

No. It can't. It simply has two AC outputs that are the same 230VAC/50Hz.

No Victron inverter offers 120/240VAC split phase output.

You can get split phase if you have 2 (victron) inverters, correct?

 

[Horsefly]

No. It can't. It simply has two AC outputs that are the same 230VAC/50Hz.

Does Victron allow the 50Hz vs 60Hz to be selected? I thought I had seen that.

 

[noenegdod]

This is kind of off topic but has anyone ever considered using structural aluminum above ground as a conductor? You can get 24' lengths and weld or bolt them together. I just bought several hundred feet of 2x2x1/8wall HSS for ~$4/ft . Its cross section of aluminum is just under 1". They could easily be installed on posts at a safe height with inexpensive insulators.

Edit: They were 20' not 24'

 

[sunshine_eggo]

You can get split phase if you have 2 (victron) inverters, correct?

Yes. Exact same model and preferably the same firmware; however, this is NOT desirable for you. The 120VAC items would experience a much worse voltage drop. You want the 500/300' runs at 240V.

Does Victron allow the 50Hz vs 60Hz to be selected? I thought I had seen that.

Yes, and the 230VAC units can be bumped up to 240V.