Kilowatt Power

I've had great success at a student hostel with the 4A version of these current limiting protective devices. Culprits get disconnected for 60s whenever the load exceeds 920W.

Yes. 3 CT coils are installed with the same polarity on each phase. Had to change the direction of all 3 CT coils when I realised energy was being exported to the grid. Shall get pictures when I next visit the site.

The 15kW load runs from 8am to 4pm. Maximum solar production is at 12 noon when the sun is directly overhead.
North East happens to be the building azimuth angle. I would however want to believe that direction becomes less significant as the tilt angle approaches 0°. I read somewhere that  a horizontal roof has a tilt angle of 0° and an azimuth angle of 0°
I want to believe so. It's correctly displaying V, A, %THD, Hz, PF, kW, kVAr, kVA, kW and import/export kWh and kVArh. Most importantly it's communicating with the inverter and preventing grid feed-in. Shall peruse the manual once more and go through all settings just to be sure.

The mounting structure is fixed. The 5° tilt angle was to allow for rain to naturally clean the panels. Having said that, I'll get the panels hosed down once again to completely eliminate the possibility of dust curtailing production.
Wasn't measured. Shall try getting readings with the clamp meter thermocouple probe at high noon.

I know my suggestion was a long shot and the efficiency shouldn't be as low as yours. Thanks for that efficiency curve. Haven't seen it before.
Do you have some sort of a monitoring app which can provide a full day V/A curve for each MPPT? That should at least tell you if you are lacking on the volts or amps. Something like this Solarman graph from my SunSynk inverter. I have ran a full load for the whole day and your site is pretty much doing the same from 8AM to 4PM. 

 

The 3-phase string inverter doesn't have the exact menu options as the hybrid but enabling unlimited export is still worth a try. I doubt if the utility meter will enter into tamper mode as a result. The worst that can happen is for the meter to count exported energy forward. 
The string inverter has options for a limiter or smart meter. Opted for the Eastron CT smart meter.
Thanks. 
SUN-25K-G03 is a grid-tied inverter. Everything is on the grid side, after the main incomer MCCB. 

The grid standard does not specify the maximum size . It normally just sets the limits on min and max volts at which point the inverters must disconnect. The standard also sets the frequency limits of operation. That is normally set by the grid supply authority. By using more panels mean you are increasing the voltage so for the same load the amps will be lower. Further more panels as indicated would just mean less power from the grid. 
Not sure which grid standard one would apply in the country where the system is installed but don't see a problem using the ZA grid standard or the EU standard. AUS also fine but I think they are stricter on the volts and freq limits. Their standard might also include a system where they have control over the inverter to switch it off if grid ties are moving the network into an unstable region. 
G83. 3 or G100 standard should  also be fine I think. Have not looked at other standards. 
My 2c on what I can remember which at times is dangerous. 
 

Some clarity and information about wiring and using of SPD'S in DC and AC curcuits. We had a discussion and concerns as where and how the SPD'S should be wired in solar combiners and AC db boards. This article in LikkedIn presented by ONCYY tier1 producer of dc and solar protection devices.
https://www.linkedin.com/pulse/why-surge-protector-preceded-fuse-circuit-breaker-onccy

I've had great success at a student hostel with the 4A version of these current limiting protective devices. Culprits get disconnected for 60s whenever the load exceeds 920W.

I've had great success at a student hostel with the 4A version of these current limiting protective devices. Culprits get disconnected for 60s whenever the load exceeds 920W.

Correct statement and to just add to it,  it is essential that cables between battery and inverter needs to be short as possible as the de-rating with longer cables is actually very real. I use these formula to determine cable size in mm².
Current/3 = Cable size in mm² up to 5 meters. For example: if the current is 200A, then the cable needs to be:  200/3 = 66mm² for 5 meters so closest cable size is 70mm².

I've had great success at a student hostel with the 4A version of these current limiting protective devices. Culprits get disconnected for 60s whenever the load exceeds 920W.

Yes, but the Axpert machines can only entertain the Pylon RS485. This is opposed to Deye/SS that can entertain Pylon Canbus as well. 

It looks to be a Seplos BMS in your battery so google that.

Off the top of my head, your PS4 power supply cannot "ride through" the 20ms transfer time of your SNA 5K inverter.
Not sure but try changing the AC input voltage range setting from APL to UPS to reduce the transfer time from 20ms to <15ms. 

 

Off the top of my head, your PS4 power supply cannot "ride through" the 20ms transfer time of your SNA 5K inverter.
Not sure but try changing the AC input voltage range setting from APL to UPS to reduce the transfer time from 20ms to <15ms. 

 

Off the top of my head, your PS4 power supply cannot "ride through" the 20ms transfer time of your SNA 5K inverter.
Not sure but try changing the AC input voltage range setting from APL to UPS to reduce the transfer time from 20ms to <15ms. 

 

Do you have specs for your panels i.e. Pmax, Vmp, Imp, Voc & Isc? 
 
MPPT, short for maximum power point tracker, is electronic circuitry (DC to DC converter) that optimises power extraction from solar panels (or wind turbines) to the inverter or battery system, as weather conditions vary. A good analogy of an MPPT as a vehicle's transmission system, offering power from the engine to the wheels is explained here.

Off the top of my head, your PS4 power supply cannot "ride through" the 20ms transfer time of your SNA 5K inverter.
Not sure but try changing the AC input voltage range setting from APL to UPS to reduce the transfer time from 20ms to <15ms. 

 

The way to calculate the conduit size as per wire cross section is to use cable spacing factor. Stranded 10mm² factor is 146. 20mm conduit factor is 460. So 3 x 146 = 438. So yes you can use 3 x 10mm² stranded conductor(gp wire) in a 20mm pvc conduit. 
 

Was the SPD the main cause for reduced string voltage?
All in all, I'm glad that you're now getting reasonable voltage and that you can now proceed with optimizing your PV setup by adding 2 or more panels. 

To @GreenFields, @Kilowatt Power, @Scorp007 and anyone else I might have missed, thank you very much for the very insightfull information on the panel efficiency and what I should install given my setup. Your contributions are pinpoint and valuable! 

@Sc00bs @Kilowatt PowerWhile we are on the topic of generators and it is my last day of leave before flying to JHB i have time to discuss and explain  "portable generators" the safety aspects and the reason some generators not accepted by inverters as input power.
In South Africa we have this wonderful part of our lives that occurs at a near daily basis, called load shedding. In the current state of things people are running to buy which ever and what ever generator they can and often times these people have no idea of what exactly they are purchasing.
Most people purchase your average little Honda/Chinese/etc 2.5 – 5.5 kVA generators and a percentage of these people would want these things wired permanently to their homes/businesses. There are a few problems with using these generators as permanent on site generators supplying equipment and house holds.
The first problem that we must get through is a simple matter of design, these generators are designed to supply appliances and specific equipment , not really households and all the required safety devices, most of these generators are of the center tap type meaning that they have 1 secondary winding split into two by means of a center tap, this generates a ‘two phase supply’ in most cases on your connection considered to be live you will get a voltage of around 150 Volts and on the connection considered neutral you should measure around 70 volts, which makes up your 220 Volts.

This brings us to problem number two in this discussion, being the safety, with these generators connected to your house your earth leakage will not work and you will experience nuisance tripping, this just increases the risk of electrocution. The other safety problem that arises is that of earthing, you cant effectively earth your alternator on your generator, and because of this the potential to earth is far greater and causes more danger in respects to earth fault. This poses great danger for human beings and animals who come into contact with this installation because an unearthed system creates the possibility of you becoming the Earth continuity conductor and being electrocuted.
These two problems collate and are part of the reason we find the following in SANS 10124:1 regulation 7.12.2.7
‘7.12.2.7 A 230 V generator with a V-O-V earth connection (centre tap on winding which is earthed), shall not be connected to a fixed electrical installation. Amdt 6
NOTE Such a generator may be used as a free-standing unit to provide power to specific appliances. Amdt 6′
 
The solution to this problem is a bit out of the ordinary, but quite simple, ask your electrician to remove your center tap and isolate it, there after you earth the neutral side of your winding and potentiality create a TN-C-S system on your generator, which is legal. and therefore you can now comfortably issue a COC for the installation.
Lastly electricity, like firearms has a very, very long history of deaths following it. So safety is the number one priority.

Just bear in mind that the inverter will rejet AC input of a portable generator with hard N-E bond in place....