Morning Everyone, I,m Andre, a newby and very appreciative of being able to join your group.

Living on a farm I can't afford to keep on throwing money down the drain at a rate of R3400 per month before I flip a switch. I'm going off grid so I need the most affordable option. Regrettably I'm locked into a 3 phase setup due the my borehole pumps. I need an 8-10kW setup and have been looking around for small off grid/hybrid inverters in the 3-4kW class that can be connected up as 3 phase. There seems to be a number of makes available and I'm asking your advice on which would be the most suitable. The sales agents are not keen on helping in this regard and are trying to sell their 12kW 3p systems which I can't really afford. They give no specific reasons, only saying it is a short term solution to a long term problem. What are the cons of such a three inverter system?

A last remark is the very high number of scam sites I am encountering in my search for components and info. Can you please list the reputable companies that you have dealt with?

Regard

Andre

30 minutes ago, ATB said:

Regrettably I'm locked into a 3 phase setup due the my borehole pumps. I need an 8-10kW setup and have been looking around for small off grid/hybrid inverters in the 3-4kW class that can be connected up as 3 phase

I'd suggest you do the sums and you'll quickly discover that it's far cheaper to convert these pumps to 1ph first.

Don't throw good money after bad, 3ph only becomes a necessity when pumps get a lot bigger. ( 7.5kW +).  

But mostly 2/3rds of your investment is not doing anything when you not pumping, if that was a 1Ph system it could be smaller and save you a whack.

The next thing to consider is that most, (not all) inverters can't handle pump starting current. The more affordable inverters being the first to be affected. Even the ones with enough low- down grunt will have to be over-rated to make sure they are up to the job. This applies both to 1ph and 3ph.

If I were you at this moment in time I would consider looking at converting to a lower power 1ph pumps and pumping for longer, and finding out what savings can be had swapping over to 1ph supply. 

Then take your solar plans from there....

Edited November 29, 20223 yr by phil.g00

Hey @ATB, I can give you some great suppliers and even a distributor that would be able to get you a decent pricing via DM if you want.

Otherwise, I know that it often isn't worth it to convert from 3-phase to single phase so good call on that one. The conversion just means that you will be connected to one of the phases instead of 3, but that means you'll need to get a sparky in to rewire and CoC the building before even looking at inverter installation. Then there's the cost of replacing pumps and 3p equipment, it becomes an expensive endeavor if you need to work within a budget.

I assume you are aware of the of the Infinisolar 3p 10-15kw systems, they aren't bad and come at a decent enough price. You can also make your own 3p circuit using 3x 5kW inverters, getting a little more bang for your buck and it would cost more along the lines of 15K rather than 30-40K for the inverters. Also, if you want cheaper short term batteries batteries are a fine option as well. While we would all love to get a fancy system we don't all have the cash for something so complex, do I get you man.

1 hour ago, ATB said:

I'm locked into a 3 phase setup due the my borehole pumps

Hi Andre, if you are interested in the possibility of running your borehole pumps independently, I have recently installed a microcare solar pump controller for my 1.1kw 400V borehole pump. It is an easy unit to set up and runs straight from the panels so no need for batteries and has a built in VSD with soft starter and is built for purpose so I expect it to last much longer than a regular inverter and it lives outside under the panels and runs automatically when the sun is strong enough. The only issue might be that each pump will need its own controller and panels so it depends how many pumps you have and how much power they need. I run 18x100W panels in series (820Voc) for a 1.1kw pump.

https://www.sustainable.co.za/products/microcare-portable-1-5kw-380v-220v-solar-pump-inverter

 

8 hours ago, Psy said:

but that means you'll need to get a sparky in to rewire and CoC the building

It means the 3 phases get bridged at the incomer to the single incoming phase. 2 loops and 2 minutes work.

 

Thanks All for your input so far.

We have considered all the options mentioned but re-wiring the entire system or going stand-alone on the pumps are not viable options due to costs, distances, cable sizes thefts and uninsurability of these items.

The most cost effective solution seems to be a 3 inverter parallel 3 phase system. Just trying to find out why the sales agents don't recommend it as it seems to be quite popular in agriculture and industry.

I would recommend a 12kW SunSynk. You don't say what you are considering, but I assume it is 3x 3kW Axpert/Kodak inverters? I don't think they will satisfy your needs - they don't have a non-essential load side, and also probably won't allow enough passthrough current for your needs.

Thanks P1000. This is the advice I need. Would Luxpower 5kW or SRNE 3.3kW work?

3 hours ago, ATB said:

Thanks P1000. This is the advice I need. Would Luxpower 5kW or SRNE 3.3kW work?

The Luxpower SNA is also an Axpert AFAIK. SRNE most likely also.

Thanks again. This re-packaging thing is something to get used to.

@ATBwill you keep the Eskom Grid as a backup or still connected ? The answer to this question will say a lot for what type of equipment to buy & how it will work. 

Morning Steve.

No eskom. will be totally off the grid.

As much as I would say it makes sense to get the Sunsynk or Deye, unfortunately it's not a purely off grid inverter. There is a large portion of that machine that is Grid tied & you paying for quite a bit of that portion of the machine which you will not make use of. I would suggest the either 3 X 5kW Voltronics machines on Single phase to make up the 3 phases. Or the infiniSolar 15kW 3 phase machine. 

It supports Pylontech batteries & if you wanted to buy the best priced Felicity Solar batteries the RS485 would pair with all the Voltronics inverters I mentioned above. 

The 5.6kW OGS5.6 is out of stock but the 7.2kW & even the 10kW single phase machines as purely off grid cannot be beaten in terms of price & reliability. 

The infiniSolar machine is the latest version of that machine & I know many will shoot it down based on the older version. I have worked with this machine & it is light years ahead of the old Infini. 2 AC output load ports that can be Remotely controlled & configured to cut off at a specific % SoC. 

But without the Grid I would not waste valuable budget on the Deye/ Sunsynk. You on a farm. You need redundancy & also a machine that gives you the most options as possible. All the Voltronics machines offer that. 

I install both types. This user requirement meets the Voltronics hands down. 

Thanks a lot Steve.  Do you have model numbers for the Voltronics and InfiniSolar? There seems to be a lot of variations ie RCA Mecer etc.

The batteries will be either Felicity solar 8,7/12 kW or Vestwoods 9,6kW. Panels looks like Canadian give the best value.

I would stick the Segen Branded versions like Kodak & Blue mountain energy version of the infiniSolar. I will PM you models & pricing etc. The only reason I say to make use of Segen is because of local backup & support. They have a very extensive R & D team that deals with all their products before they release them into the wild. The infiniSolar 15kW 3 phase machine was in their lab for at least 4 months running integration testing with all the batteries that the OEM in China stated were supported.

I visited their lab during the testing phase & the machine came through the testing phase with very good results. 

Segen branding sounds fine and makes a lot of sense just sorry they don't sell direct to the public.

Hi All. Been off for a while with a near collapse of our cell/internet system with the load shedding and bad weather. In which order would you rate the 5kw 48v inverters of the following manufacturers? Rentech, Luxpower, Must and Growatt.

3 minutes ago, ATB said:

Hi All. Been off for a while with a near collapse of our cell/internet system with the load shedding and bad weather. In which order would you rate the 5kw 48v inverters of the following manufacturers? Rentech, Luxpower, Must and Growatt.

Luxpower

Rentech-longer warranty on Axpert type inverters

Growatt

Must

from my limited knowledge of these brands.

On 2022/12/01 at 9:01 AM, Steve87 said:

As much as I would say it makes sense to get the Sunsynk or Deye, unfortunately it's not a purely off grid inverter. There is a large portion of that machine that is Grid tied & you paying for quite a bit of that portion of the machine which you will not make use of. I would suggest the either 3 X 5kW Voltronics machines on Single phase to make up the 3 phases. Or the infiniSolar 15kW 3 phase machine. 

It supports Pylontech batteries & if you wanted to buy the best priced Felicity Solar batteries the RS485 would pair with all the Voltronics inverters I mentioned above. 

The 5.6kW OGS5.6 is out of stock but the 7.2kW & even the 10kW single phase machines as purely off grid cannot be beaten in terms of price & reliability. 

The infiniSolar machine is the latest version of that machine & I know many will shoot it down based on the older version. I have worked with this machine & it is light years ahead of the old Infini. 2 AC output load ports that can be Remotely controlled & configured to cut off at a specific % SoC. 

But without the Grid I would not waste valuable budget on the Deye/ Sunsynk. You on a farm. You need redundancy & also a machine that gives you the most options as possible. All the Voltronics machines offer that. 

I install both types. This user requirement meets the Voltronics hands down. 

Hi Steve

 

I am running such a setup and have noted that the SMH under the "Inverter TAB" shows the same inverter serial number for P1 and P2

Have you ever used a Three Phase Kodak/Axpert Setup with Centurion Solar's SMH? 

 

Hey Windgat sorry I have not made use of the Centurion product. 

Thanks Scorp007, wondering what the others are thinking?

Hi @ATB

You don't need to replace your 3-phase borehole pumps if you want to convert to a single phase system.

You can install a 3 phase VSD on the pumps, will run the pumps 3phase of a single phase supply. Will also give  you a soft start so as to not overload the inverter when the pumps start up and speed control if desired on the pumps.

I have used the Veichi ones in the past but there are a number of manufacturers who make them.

 

You can run up to a 1.5kw 3 phase motor off 230v single phase using a Veichi AC70E, pretty cheap @ R2800

https://cfptechnologies.co.za/product/veichi-ac70e/

 

Otherwise they have a VSD designed for solar conversions, allows you to run either using a DC 150V-450V or AC230V power.

https://cfptechnologies.co.za/product/veichi-si23-d3-series/ if you want to maybe run the pumps directly off solar panels & a 230V Single phase 

 

Would suggest speaking to CFP for the product best suited to your requirement. 

 

Then  you don't have to worry about balancing loads on a 3-phase supply etc.

 

Edited December 18, 20223 yr by Sc00bs

Thanks Sc00bs. We have spoken to a number of experts on this issue but it is not workable due to the distance and cable size. A stand alone system also will not work due to theft and uninsurability.