Recommendations for a 24v system to 120/240v?

[Moonlitmile]

Hi I’m starting my first solar system for my 19’ motorhome. I have sourced 4-315 watt solar panels for $1000 bucks. I live in Vancouver so if anyone is looking I can direct you to the source!

Ok I think I will go with a 24volt system and I need to power a 208-230 volt 1phase 25seer mini split AC unit, and a 250w 120v laptop, though the power adapter for the laptop says 100v-240v so maybe I can rewire the unit to run 240?

I’ve been looking at options for a inverter/charger for over 2 weeks now and can’t make up my mind and now going a little crazy! I’d like to have the option for a 120/240 inverter charger combo but having the hardest time choosing as the good ones seem to run over $2200!. Maybe just a 240 volt and then a transformer to go down to 120? Or visa versa?
I found a local person selling a 240/120 inverter/charger but the efficiency is only 80%

The aims 4000watt 120/240 says its 93% efficient.
Question: is that 93% efficiency for both the 120 and 220? Or just the 120?

The AC unit supposedly only draws 650watts so maybe I’m ok with the 80% efficiency loss?

Does anyone have any recommendations for what I’m looking for? Any help would be greatly appreciated!

- Jake

Edit; I have 4 12v 180ah agm batteries, in the future I will probably go to lithium.

 

[gnubie]

The adaptor for the laptop is likely a universal power supply, ie, it just works regardless of voltage. If it has a detachable mains (grid) cord and it has 3 wires ensure you get that earth all the way back to the wall outlet or where ever if you go down that path.

Using a transformer would work, but the way a transformer works effectively makes your laptop need more power, as far as the inverter is concerned. That probably won't be a problem looking at your loads vs the inverter rating.

The efficiency rating AIMs states will be the unit's peak efficiency, usually under a high load. Since it's 4kW (I'm assuming that's the inverter rating, but maybe it's solar so this may not apply) you'll never be there so you can really ignore this figure. Odds on at < 1000 watts it's pretty horrible efficiency, this is just the nature of this stuff not a statement that the AIMs is bad. You could verify the efficiency with a clamp meter if you wanted to go down that rabbit hole.

If you are looking around for an all-in-one inverter charger, take a look at the MPP Solar range. They are popular on the forum, as far as I know nobody here has managed to blow one up yet.

 

[John Frum]

Unless I know better(even if the doco makes claims about peak efficiency) I use .85 for inverter efficiency.
To size your system you need to determine the peak draw of your A/C and the average draw.
This tool will tell you determine the peak and hopefully the average draw. https://www.amazon.com/gp/product/B07P323914/
Is this a mobile setup or stationary?
Will you be using shorepower?

 

[Steve_S]

Hi I’m starting my first solar system for my 19’ motorhome. I have sourced 4-315 watt solar panels for $1000 bucks. I live in Vancouver so if anyone is looking I can direct you to the source!

Ok I think I will go with a 24volt system and I need to power a 208-230 volt 1phase 25seer mini split AC unit, and a 250w 120v laptop, though the power adapter for the laptop says 100v-240v so maybe I can rewire the unit to run 240?

I’ve been looking at options for a inverter/charger for over 2 weeks now and can’t make up my mind and now going a little crazy! I’d like to have the option for a 120/240 inverter charger combo but having the hardest time choosing as the good ones seem to run over $2200!. Maybe just a 240 volt and then a transformer to go down to 120? Or visa versa?
I found a local person selling a 240/120 inverter/charger but the efficiency is only 80%

The aims 4000watt 120/240 says its 93% efficient.
Question: is that 93% efficiency for both the 120 and 220? Or just the 120?

The AC unit supposedly only draws 650watts so maybe I’m ok with the 80% efficiency loss?

Does anyone have any recommendations for what I’m looking for? Any help would be greatly appreciated!

- Jake

Edit; I have 4 12v 180ah agm batteries, in the future I will probably go to lithium.

Welcome to the forum. A little clarification to prevent problems, you're in Vancouver BC, our electrical system here in Canada is 240 VAC Split Phase or 120V Single Phase @ 60Hz. This means that you have two active 120V legs which are what provides 120V out of the panels, No Converter / Transformer required. 208/210/220 Single Phase @ 50Hz is Europe & Asia, the two are different and not interchangeable. The ONLY converter / Transformer you would require would be something to take the 24VDC and provide 12VDC for the support of the RV Equipment.

A 240V/Split Phae inverter will be a bit less efficient than a 120V Inverter and will cost you a slight bit more. TBH, I have only seen 240V in one Winnebego and that was aftermarket because the owner used it for a mobile workshop and some tools required 240V. If the only reason you're looking for 240 is because of that Mini-Split, I would suggest looking for a 120V Mini-Split, there are lot's of them out there now.

AIMS are ok "Value Grade" devices, all of it works per specs and does what it is supposed to. Their products have minimal interactivity & management function and some might even consider them "basic". AIMS is a VAR (Value Added Reseller) they contract with Sigeneer & Yiyen possibly others who are OEM (Original Equipment Manufacturers) and have the "devices" branded & labeled for AIMS and any particular customizations they want. They do have Sales / Support & Service in North America but it's kinda so-so from my experiences with trying to get info from them when I was considering a replacement Inverter System.

BTW: I ended up going with Samlex (Head Office for North America in Burnaby B.C.) and they answer everything and service / support is excellent. If you really want a good Inverter / Charger with lots of features & function that is commonly used in RV's & Boats then look at Samlex, note they are not cheap, it is a Tier-1 product BUT you do get what you pay for ! See Samlex Link in my signature for more detailed info and comparison info.

REFS:
Samlex: https://samlexamerica.com/products/Category.aspx?cid=M11 (look at Pure Sine 1 AC Input & 2 AC Input, the top two in the list)
Sigineer: https://www.sigineer.com/product-category/inverter-chargers/
Yiyen: https://www.yiyen.com/solution/off-grid-inverter-inverter-selection-guide/

Note: I have a Yiyen APC-3024, Pure Sine, LOW Frequency, Inverter/Charger which I used for 2 years before switching up to the Samlex. It worked "OK" and supports Lead Acid batteries fine but NOT Lithium Based batteries. Still MANY of the Yiyen / Sigineer and lower "Value" level gear are generic in battery type support without specific support for the various Lithium Chemistries. As I converted from Big Lead to LFP (LiFePo4) I wanted to ensure that I could program exactly what the batteries need as it is the "Big Investment".

Apparently, IF viewing from Phone, signatures are not shown ? so I'm told.
Samlex Link from my Signature: https://diysolarforum.com/threads/s...uts-bms-controllable-fully-programmable.2268/

 

[MichaelK]

For my own workshop, I installed Schneiders 24VDC to split-phase 120V/240VAC inverter Conext SW4024.

Schneider Electric Conext SW4024-120/240 Inverter/Charger - RES Supply

Free Shipping! Schneider Electric Conext SW4024-120/240 Inverter/Charger, 4000W, 120/240VAC, 50/60Hz, 30A Transfer, 24VDC, 90A Charger, RNW8654024

ressupply.com

It's designed to be wired into a standard household mail electrical panel providing 120V/240V service. It's a serious, Tier 1 product.

My personal experience though is that 1260W of panels is not going to power your unit if it requires 650W. I'll assume they will be laying flat on the roof, and maybe at noon they might reach 50%, or almost 630W, but for most the the afternoon when you want the air-con on, the sun will be lower in the sky and have even less than 50% output.

Before you embark on this journey, I'd hoist one of your panels up on the roof and measure it's real-world output under natural conditions. I'd expect it to be outputting far less than what you're hoping for.

BTW, 1000$ is not really a good deal for 1200W of panels. My last purchase of 1000W of brand-new panels was 400$, and most recently, 1000W of like-new panels for 220$.

 

[Fred S]

For chiming-in's sake, I bought this last fall:

Amazon.com: SUNGOLDPOWER 4000W Max 12000W Input 240VAC Split Phase 120V 240V Output Pure Sine Wave Inverter Charger Solar Wind Power Inverters 65A DC 24V Converter: Garden & Outdoor

Amazon.com: SUNGOLDPOWER 4000W Max 12000W Input 240VAC Split Phase 120V 240V Output Pure Sine Wave Inverter Charger Solar Wind Power Inverters 65A DC 24V Converter: Garden & Outdoor

www.amazon.com

Only Chinese email support of course. Edit: Come to think of it, I think they have a phone # too. I've never used it.
It looks exactly like an AIMS - perhaps relevant to Steve-S's excellent comments, ha.
It has worked 24x7 without a hitch. I use one of the 120v legs to run 2 small fridges and a freezer, and if the grid is out I use the 240v for a well pump.

 

[MichaelK]

Looking at the owner's manual for this SunGoldPower inverter, I spotted some red flags that I would be very concerned about. Here's a snip.

Ten percent total harmonic distortion strikes me as being very high, and the peak efficiency is quite low. Can the electrical engineers here chime in about what this means in the real-world? I take it to mean it produces dirtier than average power, and produced it at lower efficiency than other higher quality inverters. Not the kind of inverter I'd want to use to run high-value equipment.

 

[gnubie]

The mains (grid) isn't all that clean either, often flitting around 10% too. It's not at all unusual to see crest distortion from all the cheap and nasty switching power supplies in so much equipment today. So long as it's reasonably sinusoidal I wouldn't be too worried about the 10% figure they quote.

 

[Fred S]

Yeah, it's a shame it's not 3% THD. I might not drive a server room with it, but with induction motors, not too worried. If I had a scope, I'd have a look out of curiosity, at different loads. If I can manage to calibrate amps pretty well (DC in vs AC out), I will check the efficiency just for yuks.