Scneider Electric 33kw string inverter installation ( Decentralized 3 x High voltage Mppt)

[TaliaB]

At last done with this installation got a few more gray hairs. Installation done at OK Liquor outlet in Witbank( Emalahleni). Total power consumtion during daytime 23kw mostly commercial fridges , upright freezers and some upright wall chillers. Will install 35kva Perkins generator that will arrive on Monday morning. 5kw Growatt and 48v 100ah Easy Power lfp that will run the office equipment.

Scneider CL33 inverter 33kw surge 40kw 2 minutes that is capable of DC-AC ratio of 1:9. The CL 33 inverter will deliver full power at unity power factor with +30% and -5% grid
voltage variation. MPPT voltage range: 200 ~ 1200 V
Full MPPT voltage range: 550 ~ 1000 V
Maximum voltage: 1500 V
Starting voltage: 250 V.                            Number of MPPT's:  3

Solar array consists of 138 x Seraphim 460wp connected 23S6P 63.48kwp.Voc of 1050v @ -13°C at STC 955v.

Edited December 1, 2023 by TaliaB

[TimCam]

Looking good.

My goodness, all those panels on the roof. Must have taken a while. Did you have a crane to assist with the lifting, or only ladders?

I see you have a battery for the office Growatt, but don't see any for the Scneider so no load-shedding protection until the generator arrives.

Hope they pay in cash, and not brown bottles.

[TaliaB]

2 hours ago, TimCam said:

Did you have a crane to assist with the lifting, or only ladders?

We used a boom lift similar to this one ladders becomes a safety risk at these heights.

 

They only need power during daytime as the fridges/ freezers when not constantly opened is not a problem until sun comes up so the 2 or 4 hours load shedding not a problem. The generator would be coupled via a central thermal unit monotoring the freezers temp and when drop of 8° the gen will activate. 

[TaliaB]

8 hours ago, TimCam said:

Hope they pay in cash, and not brown bottles.

No the group Shoprite Holdings Limited pays 60% in advance then gives you a guaranteed letter for the balance but in the contract there is a penality clause so for every day late they deduct money from the 40% that was another factor i was stressed, initially i was behind on the procerument but fortunately i finish up few days to spares as the deadline is Friday the 8th. I still need to place and connect the genset to the installation but i have ample time before "D" day. So no bottles involved

 

Edited December 2, 2023 by TaliaB
Spelling

[Antonio de Sa]

1 hour ago, TaliaB said:

No the group Shoprite Holdings Limited pays 60% in advance then gives you a guaranteed letter for the balance but in the contract there is a penality clause so for every day late they deduct money from the 40% that was another factor i was stressed, initially i was behind on the procerument but fortunately i finish up few days to spares as the deadline is Friday the 8th. I still need to place and connect the genset to the installation but i have ample time before "D" day. So no bottles involved

 

Excellent work. @TaliaB if the contract has a % penalties for late completion, you should had included a % for early completion. That is usually the case in such major contracts.

[Scorp007]

1 hour ago, TaliaB said:

No the group Shoprite Holdings Limited pays 60% in advance then gives you a guaranteed letter for the balance but in the contract there is a penality clause so for every day late they deduct money from the 40% that was another factor i was stressed, initially i was behind on the procerument but fortunately i finish up few days to spares as the deadline is Friday the 8th. I still need to place and connect the genset to the installation but i have ample time before "D" day. So no bottles involved

 

Actually the better way to have the penalty clauses. We would have less projects taking many years to complete if Gov can master this art. 

Well done on a nice project for you. You just have to keep coming back up north.

[TaliaB]

34 minutes ago, Antonio de Sa said:

Excellent work. @TaliaB if the contract has a % penalties for late completion, you should had included a % for early completion. That is usually the case in such major contracts.

Thanks Antonio yeah after generator installation and tidying up i will be close to Friday don't want them to take my labour costs quoted 

[TaliaB]

33 minutes ago, Scorp007 said:

Actually the better way to have the penalty clauses. We would have less projects taking many years to complete if Gov can master this art. 

Well done on a nice project for you. You just have to keep coming back up north.

Thanks Scorp there was actuall quite a few companies participating in the tender process but after all background checks it seems they went with me. I was also the only company in the tender process that had training by Schneider with a certificate as Scneider CL inverter installer. 

[Steve87]

Awesome project @TaliaBI have old Seraphim panels that are now at least 6 yrs old. Still generating good watts. They are also tier 1 producer. They are here in SA but unfortunately not well known.

[Scorp007]

56 minutes ago, TaliaB said:

Thanks Scorp there was actuall quite a few companies participating in the tender process but after all background checks it seems they went with me. I was also the only company in the tender process that had training by Schneider with a certificate as Scneider CL inverter installer. 

Great to see the course helped you a lot during the tender assessment. 

Great to see the ongoing sharing from our installers. 

[Bobster.]

15 hours ago, TaliaB said:

At last done with this installation got a few more gray hairs. Installation done at OK Liquor outlet in Witbank( Emalahleni). Total power consumtion during daytime 23kw mostly commercial fridges , upright freezers and some upright wall chillers. Will install 35kva Perkins generator that will arrive on Monday morning. 5kw Growatt and 48v 100ah Easy Power lfp that will run the office equipment.

 

so if I'm understanding this correctly (not a given) this is mostly a grid-tied system, and the generator will kick in when the grid goes down.
 

[TaliaB]

47 minutes ago, Bobster. said:

so if I'm understanding this correctly (not a given) this is mostly a grid-tied system, and the generator will kick in when the grid goes down.
 

How the system works. I have done the assesments on the refrigeration side as this is all it is. 18 double door coolers and 2 double door freezers for ice and 1 display cooler. The idea behind the install, to run the fridges and freezers during daytime and power them down during evenings after the doors closes. The freezers within 5% margin between them will rise from -17°C to -12°C in 17 hours.( no doors was opened) The fridges was set at 8°C and would rise to 13°C some 14° in 17 hours.

 The temp of all the fridges was dropped to 2°C and after 17 hours we measured 9°C. This concept was approved as a means of power saving and there is no risk for product contamination.(liquor what could go wrong) The complete process is controlled via a Siemens Plc Simatic-S7-1500 that was programmed by myself using STL language. Should the freezer temperature rise to -5°C it will trigger the contactor either supplying utility or the gen if in LS at night. Futher to that the plc also controlls the fridge/freezer startup after complete powerdown to start up 1 minute apart to avoid huge start up current.

This concept if successful will be implemented at other liquor stores.

The Growatt covers the lights, tills paypoint machines and wifi during LS.

So @Bobster.it will only use utility if any refrigeration temp setpoint is breached and the plc will detect and take appropriate action . It also monitors current flow from each h-vac unit to ensure that if the temp rises it is not a fault on the compressor(breakdown). The plc gets a reading from the MPPT's,(CL33) and if solar output drops below setpoint it will decide utility or gen( Ls)

 

[Steve87]

That is one very important aspect doen very well in this case study: One cannot just spend endless money. There is so much that can be done with load control & staggering. 

Very well done here @TaliaB

[TaliaB]

5 hours ago, Steve87 said:

That is one very important aspect doen very well in this case study: One cannot just spend endless money. There is so much that can be done with load control & staggering. 

Very well done here @TaliaB

Thanks @Steve87coming from you says a lot sometimes the obvious is not obvious i think it is human nature to follow the lifestyle we are use to during hard times we all need to sacrifice something for us in SA it is load shedding. We are always in the mindset what could we add to stay on par, bigger batteries, bigger inverters, bigger solar arrays, but maybe just maybe me must stop and think where and how can we save on power consumtion and still be content. Not to keep up with the Joneses, mine is bigger than yours but to think out the box how can i manage my load( like you said load control)and be happy . 

[Scorp007]

On 2023/12/02 at 8:00 PM, TaliaB said:

Thanks @Steve87coming from you says a lot sometimes the obvious is not obvious i think it is human nature to follow the lifestyle we are use to during hard times we all need to sacrifice something for us in SA it is load shedding. We are always in the mindset what could we add to stay on par, bigger batteries, bigger inverters, bigger solar arrays, but maybe just maybe me must stop and think where and how can we save on power consumtion and still be content. Not to keep up with the Joneses, mine is bigger than yours but to think out the box how can i manage my load( like you said load control)and be happy . 

Very well articulated. In line with what you say is why I am contend with my 3kVA Axpert clone and 2x small grid tied inverters. This is my own essential and non essential DIY hybrid. 

[Gerrie]

On 2023/12/01 at 6:48 PM, TaliaB said:

Full MPPT voltage range: 550 ~ 1000 V
Maximum voltage: 1500 V
Starting voltage: 250 V.     

Great work and thanks for sharing, do you use the standard 1500VDC solar cable or is there another higher voltage solar cable for these high voltage systems?

[Scorp007]

26 minutes ago, Gerrie said:

Great work and thanks for sharing, do you use the standard 1500VDC solar cable or is there another higher voltage solar cable for these high voltage systems?

Here the main specs for PV cable. 

Life expected to be 25yrs.

 

Edited December 5, 2023 by Scorp007

[TaliaB]

24 minutes ago, Gerrie said:

Great work and thanks for sharing, do you use the standard 1500VDC solar cable or is there another higher voltage solar cable for these high voltage systems?

@Gerrie

The pv cabling used is 6mm² ZW  cable that was supplied by Schneider to use on their CL range of high voltage inverters. Specifications below copied from the spec sheet unfortunately file size to large to upload.

Electrical Parameters:

Voltage Rating : AC 0.6 / 1.5 kV Max. PV - System Voltage : DC up to 2.5 kV Max. Permissible Operating Voltage in AC Systems : 0.7 / 1.5 kV Max. Permissible Operating Voltage in DC Systems : 0.9 / 2.5 kV Test Voltage : AC 6 kV / DC 10 kV (15 min.)

[TaliaB]

Final pictures on this project.

40kva FAW generator was installed and commissioned 2 days before deadline, fully integrated between the DSE 705 ATS and the Simatic S7-1500 plc. Feedback from store manager is very favorable for the project and seems to be working seamlessly. The project will be monitored to determine the viability(ROI) for expansion to other outlets within the group.