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Looking For Low-Frequency Inverter

mdraselkhan

New Member
Joined
Aug 4, 2024
Messages
3
Location
Barishal, Bangladesh
I'm looking for a low-frequency 5-12KW hybrid or off-grid inverter for long-time use. Could you please suggest something to me based on your experience? I will use Inductive loads such as a rice cooker, AC, Water Motor, and some lighting loads. At least the PV voltage should be 150V. AC output voltage should be 220-240V.
 
With AIO's (All In Ones" which combine Solar Charge Controller(s), the Inverter & Charger into one modular unit are most often High Frequency (far cheaper), not very many AIO's are available with Low Frequency inverters. The few that are out there are quite expensive in comparison and to be honest, their internal MPPT Solar Controllers and not the greatest (regardless if High or Low-Frequency inverter model).

The most optimal (but more complex) is to use independent Solar Charger Controllers and if you need more, install the SCC's in Parallel, each having their own solar arrays. Note that there are very good SCC's that can take 150/200/250 VDC Input that can output between 75A to 125A charge current. Again, only Quality Tier-1 products deliver at highest efficiency & with the least long term troubles.

Unfortunately, I do not know what the Market for Solar Componnts is like in Bangladesh and what is or not available to you or what you can import from what countries. Confusing Times lately with stupid politics screwing everything up for regular/normal people worldwide. If ONLY everyone could get along...

Low Frequency Inverters vary a lot, especially in the Efficiency Department ! Value Grade (Cheapo's) can be as low as 85% Efficient and have a High Idle consumption while a Tier-1 Quality unit like Samlex (which I use) can be up to 97% Efficient and only use 18W in idle (non-eco mode). Idle & Standby consumption can waste a LOT of power in a fairly short period of time and of course the efficiency is a point that has to be accounted for with regards to overall consumption and waste.

Budget is always the problem and most especially if there are "import issues" with duties & extra taxes etc. There are several High Quality products available from China, US & EU as well as junk ! Brands like Victron are of course Tier-1 Quality and fortunately they have dropped many prices down recently so they are more cost effective now.

You need to better evaluate & explain your "needs" and then wants.
What Voltage Battery system do you want ?
How many AMPS @ 220VAC Voltage do you need and what would you like to have available.
A LOT more equipment supports 220VAC/50Hz than any other voltage so at least your lucky with that one, better choices.

Generally we suggest that an Inverter not pull more than 250A from a Battery System.
48V (51.2V for LFP) at 250A provides 12,800W gross, which translates to 220VAC/58.18A.
Gross meaning, not accounting for losses & inefficiencies. Assume 10% loss.
 
Here in Thailand, the LVTOPSUN inverters seem like a good product. I have installed a 3kw toroidal (LF) LVTOPSUN unit--the manual for this is posted in the resources section of this board. They also have 6kw units, and perhaps larger.

The 3kw inverter is presently powering a rice cooker, refrigerator, washing machine, iron, sound system, video projector, mobile phones, a laptop, and all of the LED lighting for the house--of course, not all at the same time, but it has never been overloaded yet. It's been going strong for nearly four months now, powered by a 48-volt power wall LiFePO4 battery charged by the inverter and two separate EPEVER charge controllers.

I think the LVTOPSUN brand is only marketed in Southeast Asia, though. There are some "no name" toroidal inverters that tempted me when I was looking for one, but I haven't tried any of them, so cannot be confident to recommend them.
 
I'm looking for a low-frequency 5-12KW hybrid or off-grid inverter for long-time use. Could you please suggest something to me based on your experience? I will use Inductive loads such as a rice cooker, AC, Water Motor, and some lighting loads. At least the PV voltage should be 150V. AC output voltage should be 220-240V.
Try, Sigineer Power. Their inverters last far, far longer than those cheap high-frequency transformerless inverters, and they provide a much higher surge capacity and won't damage your appliances like a high-frequency inverter can.
 
I'm looking for a low-frequency 5-12KW hybrid or off-grid inverter for long-time use.

What are your electronics building skills like ... maybe build a Warpverter.

Will need separate charge controllers though coz it's just an inverter. :)
 
Try, Sigineer Power. Their inverters last far, far longer than those cheap high-frequency transformerless inverters, and they provide a much higher surge capacity and won't damage your appliances like a high-frequency inverter can.
those were one of the units I wanted to test and play with... especially as they had units up to i think it was 20kW at the time.
 
those were one of the units I wanted to test and play with... especially as they had units up to i think it was 20kW at the time.
What do you mean by "at the time"? Does Sigineer still market 20kw toroidal inverters?

HERE is one for 12kw. And then there is this....

18000 Watt 48V Pure Sine Wave Inverter Charger 120V / 240Vac


But that is still not a 20kw unit, and they say it does not come with a solar charge controller, which leaves me to wonder what sort of "charger" it actually is.
 
They still have the 20kW model but it's significantly more than the 18kW so financially not the optimum choice.

Thank you so much. For some reason I didn't find that page when I looked. Actually, although it _is_ pricey, if I could acquire one here in Thailand I would be willing to cough up that amount. Quality is worth its price, and I have a grid-tie situation that I would like to adapt just as this unit claims is possible. I need to remember this link! (Still in the research phase for a total system build, but this unit just made my top 5 list--if it can be obtained!)
 
Thank you so much. For some reason I didn't find that page when I looked. Actually, although it _is_ pricey, if I could acquire one here in Thailand I would be willing to cough up that amount. Quality is worth its price, and I have a grid-tie situation that I would like to adapt just as this unit claims is possible. I need to remember this link! (Still in the research phase for a total system build, but this unit just made my top 5 list--if it can be obtained!)
Just be aware that's got a pretty significant idle consumption of 280W.
 
Victron inverters are low frequency. But you'd have to do a separate charge controller.

 
So, split phase, 60 Hz. is ok with your system?
I'm not sure who I'm asking this question at now but it probably applies to the OP in Bangladesh and Norwasian in Thailand.
I'd need a 220/240 volt system, at 50 Hertz. Perhaps I misunderstood the usage of 120/240 listed on that page. I had understood it could accommodate either. If that is not the case, I may be reconsidering and looking for some other option. As they said, however, it is the largest wattage unit that comes with a heavy transformer on the market. That's attractive to me, regardless of the idle consumption. During solar hours, panels can provide that idle amount easily enough, and for night use, I have next to nothing on at night anyhow, so batteries could handle it.
 
I'd go with one or two of these then? Should be available locally in Thailand.

I have yet to find Victron anything for sale anywhere in Thailand. Now, if you know of a Thai source, I would be most pleased to be proven wrong.
 
Looks like there's a place in Phuket, they should be able to order any part on the victron price list as they prob don't have big quattros in stock:


Again, thank you very much. This seems like a major breakthrough toward real quality product options for me here. I will definitely keep this business in mind when I plan my next solar purchases. I note that they have no Victron inverter in stock in 48-volt models (per their website). But as you say, perhaps they could order them. I will have to contact them to find out.
 
Again, thank you very much. This seems like a major breakthrough toward real quality product options for me here. I will definitely keep this business in mind when I plan my next solar purchases. I note that they have no Victron inverter in stock in 48-volt models (per their website). But as you say, perhaps they could order them. I will have to contact them to find out.
Yeah I'm sure they focus on marine setups, wouldn't expect them to necessarily have any 48V gear in stock.
 
What do you mean by "at the time"? Does Sigineer still market 20kw toroidal inverters?

HERE is one for 12kw. And then there is this....

18000 Watt 48V Pure Sine Wave Inverter Charger 120V / 240Vac


But that is still not a 20kw unit, and they say it does not come with a solar charge controller, which leaves me to wonder what sort of "charger" it actually is.
I was looking at them five or six years ago due to the at that time favorable price
 

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