May 30, 20224 yr Hi all What is the best budget-friendly 3ph hybrid inverter? Consumption is around 2400kWh on average per month. Let's say 10-15kW as a load. Phase balancing is required. Minimal battery: shortfall will come from the grid and I will cut non-essential loads during LS. I will be feeding back via old school reverse-rotation capable meters. Solis? Sunsynk?
May 30, 20224 yr 24 minutes ago, Jakes Louw said: What is the best budget-friendly 3ph hybrid inverter? Consumption is around 2400kWh on average per month. Let's say 10-15kW as a load. If you defer from back-feeding (exporting), 3 Axpert (Synerji) MKS5K single phase units would make your day. They can be connected together to a 3 phase system, providing 15kW and support a total of 12kW PV panels. But you will need a huge battery of some 100kWh. Grid-tied models are also available from Voltronic but supposedly at higher cost.
May 30, 20224 yr Author Thanks, but I'd like to back feed to build unit credits for night time consumption.
May 30, 20224 yr Author Just now, Jakes Louw said: Thanks, but I'd like to back feed to build unit credits for night time consumption. Also, wouldn't the 3 x Axperts require paralleling as well as balanced phases? I have unbalanced phases and I'm not going to spend R50k sorting that out.
May 30, 20224 yr Sunsynk 12kW seems like your best option. 53 minutes ago, Jakes Louw said: I will be feeding back via old school reverse-rotation capable meters. That is illegal.
May 30, 20224 yr Author 10 minutes ago, P1000 said: Sunsynk 12kW seems like your best option. That is illegal. Thanks. And I am aware.
May 30, 20224 yr The new Infinisolar that will be launched in SA . Will be in 10kW and 15kW size. Will also feature 2 AC outputs . You choose what you want on either. Can be Essential and non essentials.
May 31, 20224 yr Author 13 hours ago, Steve87 said: The new Infinisolar that will be launched in SA . Will be in 10kW and 15kW size. Will also feature 2 AC outputs . You choose what you want on either. Can be Essential and non essentials. Thanks. This one?: InfiniSolar 15kW 3 Phase Hybrid PV inverter (enway.co.za) The 10kW unit does NOT do phase balancing.....max 3.7kW per phase.
May 31, 20224 yr No not this one. This is the old generation or generation 2 Infinisolar. I am talking about this new IP65 version . It is still in testing locally in SA. Will be available soon but in Yellow 🤠
May 31, 20224 yr 21 hours ago, Jakes Louw said: Also, wouldn't the 3 x Axperts require paralleling as well as balanced phases? I have unbalanced phases and I'm not going to spend R50k sorting that out. NO! The individual phase units do handle their load individually. You can even parallel one phase alone with a second unit to support the unbalanced load. As a matter of fact I would recommend to buy 4 units in order to have one spare for service reliability and parallel it with the most loaded phase. In case of a failure you could replace the faulty unit with the spare until repair. That's the big advantage of installing single phase units to form a 3 phase system over buying one 3 phase unit. Edited May 31, 20224 yr by Beat
June 2, 20224 yr Author On 2022/05/31 at 11:44 AM, Beat said: NO! The individual phase units do handle their load individually. You can even parallel one phase alone with a second unit to support the unbalanced load. As a matter of fact I would recommend to buy 4 units in order to have one spare for service reliability and parallel it with the most loaded phase. In case of a failure you could replace the faulty unit with the spare until repair. That's the big advantage of installing single phase units to form a 3 phase system over buying one 3 phase unit. OK, and how do I run my 3ph appliances off 1ph?
June 2, 20224 yr 5 minutes ago, Jakes Louw said: OK, and how do I run my 3ph appliances off 1ph? I don't understand your question. 3 or more single phase units can be hocked together to create a true 3 phase system.
June 2, 20224 yr Author I know. But there is a thing called phase rotation, usually handled if the units are properly in parallel. This applies to load balancing as well?
June 2, 20224 yr 2 hours ago, Jakes Louw said: But there is a thing called phase rotation, usually handled if the units are properly in parallel. This applies to load balancing as well? Phase rotation, also called phase sequence, has nothing to do with load balancing. It is determined by the configuration of the individual units as P1, P2 and P3. They are also referred to with R, S, T. To have the right phase sequence on your 3 phase motor terminals depends on the correct wiring.
June 2, 20224 yr On 2022/05/31 at 10:46 AM, Jakes Louw said: Any idea who will stock them? Segen and many other Original Voltronics resellers. DIY Geek & Full circle Solar to name a few.
June 2, 20224 yr 2 hours ago, Jakes Louw said: I know. But there is a thing called phase rotation, usually handled if the units are properly in parallel. This applies to load balancing as well? When an installation is done with what@Beatis describing, the loads are balanced and a good sparky will make sure that the loads are balanced at the Main DB. It involves making sure the load is spread evenly throughout the 3 phases. But I can attest that 3 phase motors can run well in such a set-up. This type of Single phase Parallel to make 3 phase power is quite a task to handle and it requires more space than a single 3¢ unit. There are also some rules to how it can be successfully done. The battery pack has to be shared by all the machines. In other words you can't have the batteries on individual inverters. They need a common battery bank. So voltages must be the same. it's cheaper to acquire but more expensive to install if that makes any sense. But some good pros and less cons.
June 3, 20224 yr Author @Steve87 : thanks for that. Another issue is that the 1ph units would also have a load limit: If I have a load of 6kW on 1 phase, do all 3 units need to be 6kW?
June 3, 20224 yr 33 minutes ago, Jakes Louw said: @Steve87 : thanks for that. Another issue is that the 1ph units would also have a load limit: If I have a load of 6kW on 1 phase, do all 3 units need to be 6kW? Yes Jakes, Hence one big unit in 3phase eg. an Infinisolar 15kW will be limited to 5kW per phase. You cannot run away from a limit of this nature in the single machine operation. Maybe a Sunsynk can supply above the 3 way split but I think you cannot in any case go above the total rated capacity. However, remember that with the Infinisolar machines this limitation is only valid if there is no grid available like off grid or in a loadshedding scenario. When the grid is present and you say want to demand 6kW per phase the inverter will go into Bypass and supply directly from the grid. Once that phase requirement reduces it will once again inverter the power from available sources like PV or Battery power again. I have installed a set of 3x 7.2kW MAX in 3 phase operations and I must admit I have not gotten close to the limit yet. However, load staggering and planning is important. I planned CBI astute breakers on all of the large appliances like the 2 geysers and the pool pump/ heat pump. This a responsible way to plan to use the energy. In other words not everything comes on at the same time. The said load requirement here was to power 2 X 200L geysers, 1 heat/ pool pump combo plus a 3 phase Central AC unit. So the planning was to firstly split up these loads onto the phases. Then split the plugs and lights evenly. Once that is done then comes the CBI astute smart breakers for each. Then once all is installed and working is to plan a schedule that permits no solar losses and keeps the heavy loads staggered so they never encounter each other at the same time. The inverter Power output is 21.6kWh, The PV Array 12kW and the central Lithium Battery pack at 24kWh.
June 3, 20224 yr 1 hour ago, Jakes Louw said: Another issue is that the 1ph units would also have a load limit: If I have a load of 6kW on 1 phase, do all 3 units need to be 6kW? NO, not at all! As you can read from the installation schematics I provided, there can be i.e. one phase with 2 or more parallel units to support the extra load. No need to increase the power on the other phases. As a matter of facts, almost any combination of balanced and unbalanced phases is possible. That's another advantage of this concept.
September 12, 20223 yr Author On 2022/06/03 at 12:20 PM, Beat said: NO, not at all! As you can read from the installation schematics I provided, there can be i.e. one phase with 2 or more parallel units to support the extra load. No need to increase the power on the other phases. As a matter of facts, almost any combination of balanced and unbalanced phases is possible. That's another advantage of this concept. Just to clarify: so a 10kW 1ph inverter to handle one of the phases, and a pair of 5kW in parallel to handle the rest?
September 12, 20223 yr Hi Jakes, you can fit these individually to the system. But the rules of paralleling make for allowance of the same machine & same firmware to be installed. Otherwise nothing stops you from installing different machines in different phases but they won't work in a parallel way.
February 17, 20233 yr Author Update on this: I crunched the numbers and got some quotes. It is cheaper to actually buy an oversized 3-phase hybrid inverter than to have 3 x single-phase inverters running in parallel. Pricing at this stage for a start-up system (grid-tied, no battery) are between R100k and R137k depending on components (that was before the latest price increases) That would be a 15kW inverter, as well as 10 panels to easily satisfy the minimum PV required to activate the inverter (usually between 160VDC and 180VDC depending on model). Yes, this price is quite steep but the installation is between 20% and 30%. So I decided : bugger that, I know a qualified electrician that will help me, and I'm going to do it myself. Solis S5 15.0kW Dual MPPT 3-Phase Grid Tie Inverter - R25k Solis S5 25.0kW Triple MPPT 3-Phase Grid Tie Inverter - R38k At that price difference, I'd rather go for 25kW. MUCH for flexilibility and less chance of load issues later. The problem now is solar panels. No stock anywhere and the prices are mental compared to 3 months ago. Hopefully that clears upo soon, but in the meantime I can install the inverter and make sure there is space for optional batteries later.
March 10, 20233 yr @Jakes LouwDid you ever finish installing your system? What batteries were you planning to run with that Solis S5 inverter? Edited March 10, 20233 yr by RadSolar
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