Hi All, my first post here and thanks for the Join!

I'm not new to Inverter etc but i am new to PV and 3 Phase.

I've been running my little RCT 3kva inverter with Lead/Lithiums since 2015. lead first and then  Lith of course. That was on a single phase house and no issues.

We moved to a 3 phase house and I've been running it on one of the phases also no issues. House is split Geyser-Stove/Plugs/Lights on the 3 phases.

I'm running it on just the plugs and made do with lamps plugged in and some "extra" lightning with smart switches etc.

I'm making the plunge and just want to do it the correct way from the get go balanced according to budget.

1st option is to just get a 3 phase inverter 4kw on each phase.  this is prob the easiest but also costly.  batteries and panels.

2nd and cheapest is to do a 5kw/5kw battery and 6 panels on 1 phase...and just keep doing what i'm doing now.

3rd is to do an 8Kw inv 10kw batt and 12 panels, but also on just one phase but then i lose out on the saving etc for the geyser...lights are prob not even 500w(all led etc.)

and here my question...can I convert the house to 1 phase? or just move my geyser to the phase on inverter. or move lights and plugs on one and leave geyser on the other? one empty.

I've read that it is prob not that easy as the lines have to be balanced etc wararara....i do not have any 3 phase equipment and not looking at any. I just want to pay eskom as least possible so last option is to just convert 3 phase to 1(which seems like a waste).

Any comments appreciated 

Edited January 5, 20242 yr by Kaas

18 minutes ago, Kaas said:

Hi All, my first post here and thanks for the Join!

I'm not new to Inverter etc but i am new to PV and 3 Phase.

I've been running my little RCT 3kva inverter with Lead/Lithiums since 2015. lead first and then  Lith of course. That was on a single phase house and no issues.

We moved to a 3 phase house and I've been running it on one of the phases also no issues. House is split Geyser-Stove/Plugs/Lights on the 3 phases.

I'm running it on just the plugs and made do with lamps plugged in and some "extra" lightning with smart switches etc.

I'm making the plunge and just want to do it the correct way from the get go balanced according to budget.

1st option is to just get a 3 phase inverter 4kw on each phase.  this is prob the easiest but also costly.  batteries and panels.

2nd and cheapest is to do a 5kw/5kw battery and 6 panels on 1 phase...and just keep doing what i'm doing now.

3rd is to do an 8Kw inv 10kw batt and 12 panels, but also on just one phase but then i lose out on the saving etc for the geyser...lights are prob not even 500w(all led etc.)

and here my question...can I convert the house to 1 phase? or just move my geyser to the phase on inverter. or move lights and plugs on one and leave geyser on the other? one empty.

I've read that it is prob not that easy as the lines have to be balanced etc wararara....i do not have any 3 phase equipment and not looking at any. I just want to pay eskom as least possible so last option is to just convert 3 phase to 1(which seems like a waste).

Any comments appreciated 

Welcome Kaas. 4kw each is not a common size to do to each phase. 

5kW better and choose an inverter that you can parallel. 

8kW could be your end state and a bit cheaper than 2x5kW.

Convert to single phase. The geyser can still be used on PV by keeping it and the stove on non essential after the DB is split. This way any extra PV will be fed to non essential. These loads will not be available during LS periods but can be fed from battery when the grid is on. This based on settings on some inverters. 

If you get a single phase connection it can also be cheaper than 3 phase. 

Mis information that the 3 phase must be balanced. You can have a good load on 1 phase and nothing on the other 2. The specs or manual or some topics here will provide the % you can use if only 1 of the 3 phases are loaded. 

I hope this helps a bit. Fire away with any other questions. Some real clever guys can answer you. 

Edited January 5, 20242 yr by Scorp007

1 hour ago, Kaas said:

Hi All, my first post here and thanks for the Join!

I'm not new to Inverter etc but i am new to PV and 3 Phase.

I've been running my little RCT 3kva inverter with Lead/Lithiums since 2015. lead first and then  Lith of course. That was on a single phase house and no issues.

We moved to a 3 phase house and I've been running it on one of the phases also no issues. House is split Geyser-Stove/Plugs/Lights on the 3 phases.

I'm running it on just the plugs and made do with lamps plugged in and some "extra" lightning with smart switches etc.

I'm making the plunge and just want to do it the correct way from the get go balanced according to budget.

1st option is to just get a 3 phase inverter 4kw on each phase.  this is prob the easiest but also costly.  batteries and panels.

2nd and cheapest is to do a 5kw/5kw battery and 6 panels on 1 phase...and just keep doing what i'm doing now.

3rd is to do an 8Kw inv 10kw batt and 12 panels, but also on just one phase but then i lose out on the saving etc for the geyser...lights are prob not even 500w(all led etc.)

and here my question...can I convert the house to 1 phase? or just move my geyser to the phase on inverter. or move lights and plugs on one and leave geyser on the other? one empty.

I've read that it is prob not that easy as the lines have to be balanced etc wararara....i do not have any 3 phase equipment and not looking at any. I just want to pay eskom as least possible so last option is to just convert 3 phase to 1(which seems like a waste).

Any comments appreciated 

First question would be what is your 3 phase main incoming switch(mcb) rating? They are normally 50amps/ phase. To convert to single phase it may be possible to simply remove two of the phases and make them redundant but this will leave you with a relatively small incoming supply which may not be sufficient for your needs. If the switch ratings is 50 amps then you will have 11.5kw available for total consumption. You can still meter the resulting supply using the existing 3-phase meter. I'd also suggest for a job of this nature you should get a competant electrician in to survey the requirements and give you a quotation.

Hallo @Kaas and welcome to the forum.

First of all I would have a look at the Eskom account and determine what tariff they use to bill you and see if there is a lower tariff then I would start to plan around the lower tariff.

I found these document links on Eskom's site for the rates and tariffs, there are a lot of different tariffs so have a careful look at the documents:

https://www.eskom.co.za/distribution/tariffs-and-charges/
https://www.eskom.co.za/distribution/wp-content/uploads/2023/03/Schedule-of-standard-prices-2023_24-140323.pdf
https://www.eskom.co.za/distribution/wp-content/uploads/2023/03/2023_24-Schedule-of-Standard-Fees_V1__-01-April-2023.pdf
https://www.eskom.co.za/distribution/wp-content/uploads/2023/10/9454J-Eskom-Tariff-booklet-Interactive-final.pdf
https://www.eskom.co.za/distribution/wp-content/uploads/2023/04/2023_24-Tariff-Book_01042023.pdf

 

The cheapest 3 phase Hybrid inverter that I could find from a reputable seller is this one: https://solarwarehousesa.com/products/chisage-ess-12kw-three-phase-hybrid-inverter?_pos=2&_sid=7a8268493&_ss=r if you decide that you want to keep the 3 phase connection.

Here is the link to the manual for the inverter: https://chisagess.com/wp-content/uploads/2023/10/【User-Manual】Mars-10-14G1-LE_V4.2_EN.pdf

Ok wow! so many answers...will take me a while to reply properly...

On the 12kw...4kw per phase I read that a phase can be sustained at 6kw....so if maxed out....6kw on one phase 4on another and 2 on the last one? obv you would not want to keep it at 6kw...but would be nice to know?

quoted...

• 100% unbalanced output, each phase Max. output up to 50% rated power.

This is a pic of the breaker....

On 2024/01/05 at 6:39 PM, Scorp007 said:

Welcome Kaas. 4kw each is not a common size to do to each phase. 

5kW better and choose an inverter that you can parallel. 

8kW could be your end state and a bit cheaper than 2x5kW.

Convert to single phase. The geyser can still be used on PV by keeping it and the stove on non essential after the DB is split. This way any extra PV will be fed to non essential. These loads will not be available during LS periods but can be fed from battery when the grid is on. This based on settings on some inverters. 

If you get a single phase connection it can also be cheaper than 3 phase. 

Mis information that the 3 phase must be balanced. You can have a good load on 1 phase and nothing on the other 2. The specs or manual or some topics here will provide the % you can use if only 1 of the 3 phases are loaded. 

I hope this helps a bit. Fire away with any other questions. Some real clever guys can answer you. 

Hi Scorp007...the 4kw is just how the three phase inverter splits the load? that is for one inverter. 12kw deye or SS...

If i want to go the seperate route that will be 3x5kw which then puts me over 60k, just for that.

This quoted from another local forum

"The Sunsynk 12 kW delivers 4 kW per phase if all phases are loaded to 4kW. If the other phases are not loaded to the maximum rating, then a single phase can deliver up 6 kW. It can handle imbalances of 50% without an issue."

if this is the case then it will work perfectly for my application, with least amount of db work etc. Geyser/Lights/Plugs. 

Geyser and lights will be fine...it will only be the plugs that might ever hit 6kw. we idle at about 600w....bar kettle washing machine etc. Switch 2 on and will sit at 4.5kw easy. obv these can be "regulated" with eductaion or smart switches.

So my question is can it do 6kw? or even 5kw sustained?

appreciated!

 

 

Just adding...on the 3 phase...it will get extra load from the grid if needed? so only those limitations when there is loadshedding?

Hi @Kaas 

I was in a similar situation. 

You have 63A coming per phase that = 63A x 230V = 14,490W or 14.5kw of power 

If you install a 12kw 3-Phase DEYE/Sunsynk inverter the maximum load you can have per phase is 6kw  (total load max is obviously 12kw)

In my opinion, unless you have a specific requirement for a 3-phase supply, it is much easier to manage your loads on a single phase and usually makes more sense to just convert the house to a single phase supply as you are less likely to overload the inverter. 

The 12kw 3-phase is pretty much half way between the 8 & 16kw DEYE single phase inverters but the choice would really depend on your requirements. 

Is very easy for your electrician to convert your 3-phase DB to Single phase by disconnecting two of the phases and bridging the 3rd phase.

 

 

 

The current incoming power available is 44kW at power factor of 1 at the stated 63A.

Any comments on this would be appreciated 

 

2 hours ago, Kaas said:

Any comments on this would be appreciated 

 

All I an say is you can be very out of balance and your 3 pH will remain 120 degrees apart within the % that is quoted. 

Some systems might not tolerate such a big out of balance. I have seen as low as 15% allowed. 

It seems you have settled on 3 ph even if you don't need it. Because you have 63A incoming on each ph you can still put all your loads on 1 ph. 

Edited January 9, 20242 yr by Scorp007

Hi there, thanks all for the input...everything was taken into account....i settled for the 8kwDeye and 2 5kw volta...and 14 550w CS.

it works like a charm so i'm just playing around with settings and time and and and.

 

2 last questions....is Solar assistant worth it? i will go and read about it just now.

Cycles on a battery....let's say 6000 cycles...how are they counted? is 1 cycle to 20% DOD....Example is i take my batt down 10% a day for 8 days....so 10 a day...and back up. does that count a 1 cycle...roughly...or 8 cycles.

I'm not too worried about lifecycle as that is roughly 16 years at full depletion every day....in 15 years...lots will change and saving cents and percentages to only buy a 20Kw in 5 years for 30k does not make sense. don't quote me on that hahahaha. i would rather work my asset and get off eskom as close to 100%

 

Once again all help appreciated!!

Obv very cloudy today and batteries are 100% so only generating as needed.

This in normal load and geyser running...2 tvs...3 compers...2 fridges and and and....so all is well

 

I am not an electricity specialist in the least, so I can only tell you what I did. I live on a smallholding with 3 phase electricity and unfortunately have a 3 phase borehole pump. Since a 3 phase inverter is totally out of financial reach, I installed a single phase 5kw inverter. I then got an electrician to wire the inverter only to my plugs and lights. I left the garage and borehole pump as they are until I can replace the pump. And I need to be able to pull a welder and other heavy users in the garage. I have a solar geyser and gas stove.

On 2024/01/17 at 12:13 PM, Kaas said:

Cycles on a battery....let's say 6000 cycles...how are they counted? Example is i take my batt down 10% a day for 8 days....so 10 a day...and back up. does that count a 1 cycle...roughly...or 8 cycles.

I don't know what battery you are using, and whether all batteries are the same, but for Pylontech they define a cycle as discharging the full original capacity in Ah.

That means if you charge and discharge 10% a day for 8 days it will count as 0.8 cycles.

 

12 hours ago, Calvin said:

I don't know what battery you are using, and whether all batteries are the same, but for Pylontech they define a cycle as discharging the full original capacity in Ah.

That means if you charge and discharge 10% a day for 8 days it will count as 0.8 cycles.

 

Ok great...makes sense....well it's rated at 6000 cycles at 20%  and 3000 cycles at 0% so count cycles according to those numbers. thanks!

13 hours ago, eugenedp said:

I am not an electricity specialist in the least, so I can only tell you what I did. I live on a smallholding with 3 phase electricity and unfortunately have a 3 phase borehole pump. Since a 3 phase inverter is totally out of financial reach, I installed a single phase 5kw inverter. I then got an electrician to wire the inverter only to my plugs and lights. I left the garage and borehole pump as they are until I can replace the pump. And I need to be able to pull a welder and other heavy users in the garage. I have a solar geyser and gas stove.

Thanks! i don't have 3phase motos etc....but i saw this on another forum for sale....so maybe you can put the whole house on 1 phase and use this for your borehole pump. 5kw might be a bit light though for that and a household) Just google Yaskawa VSD...it takes 1phase to 3phase. so just this in front. So when money is available buy another 5kw inverter....then you are good to go.

Thanks, I will have a look

15 hours ago, eugenedp said:

I am not an electricity specialist in the least, so I can only tell you what I did. I live on a smallholding with 3 phase electricity and unfortunately have a 3 phase borehole pump. Since a 3 phase inverter is totally out of financial reach, I installed a single phase 5kw inverter. I then got an electrician to wire the inverter only to my plugs and lights. I left the garage and borehole pump as they are until I can replace the pump. And I need to be able to pull a welder and other heavy users in the garage. I have a solar geyser and gas stove.

Hi @eugenedp

You can run your borehole pump using a VSD drive from CFP Technologies.  

It has the advantage of having a soft start so is much less demanding on the inverter and you should be able to run a 1.5kw pump on the 5kw inverter without any issue. 

Phone him up, explain your application and tell him what size the pump is and he will recommend a unit for you. 

https://cfptechnologies.co.za/product-category/variable-frequency-drives/ 

Thank you. I have looked at the VSD option. Looks like it might work. Looks like every problem is solvable by the application of copious amounts of money.😀 

5 hours ago, eugenedp said:

Thank you. I have looked at the VSD option. Looks like it might work. Looks like every problem is solvable by the application of copious amounts of money.😀 

Either way - single ph pump or VSD will cost some money. 

I don't see that you have mentioned the kW of the current pump? 

I have come to the same conclusion. I cannot remember the size of the motor - I think it is a 1.6kw, but I am totally unsure. Does not matter anyway, I will see when we take it out.

On 2024/02/16 at 6:48 PM, eugenedp said:

I have come to the same conclusion. I cannot remember the size of the motor - I think it is a 1.6kw, but I am totally unsure. Does not matter anyway, I will see when we take it out.

Eugene : I have a three phase borehole and presently one of my home phases is backed up with battery.    What sparky did was add a relay so that if grid is off, the borehole cannot try and run with only one phase powered off the battery.

39 minutes ago, macafrican said:

Eugene : I have a three phase borehole and presently one of my home phases is backed up with battery.    What sparky did was add a relay so that if grid is off, the borehole cannot try and run with only one phase powered off the battery.

Yes, that is a good solution. However, my goal is to go off-grid so unfortunately the pump has to go. But for now, my budget is a hurdle.