profa

I went and checked and removed some covers but dont see any writing on the cables from the panels. However, on the battery cables to the inverter it says 25.00mm2. And those cables look to me like 4 gauge car sound cable thickness which I know pretty well. The cables from the solar panels look to me like 8 gauge car sound cable or about half as thick as the battery cables. Does this help? Also, according to the inverter, the panels are happily producing between 28-30v now at about half load (500w being drawn from house and to charge batteries). At full load (well when I draw more than they can produce) they produce about +-28v but obviously not near the amps they should be producing (38-39 instead of 46-47).

So......i just did a very unscientific measurement from where i know the panels are on the roof and took huge (1m estimate) steps from within the house where the panels are, to the garage where the inverter is. counted 17 steps. now wondering how the hell that could remotely even get close to 37m worth of cable 🤔🤔

So im busy chatting to the installer, he used 74m of cable from panels to inverter. 37m positive (going through fuse) and 37m negative going straight to inverter. 74m total.

One last quick question, the cable length from the panels to the inverter is about 15m give or take. The cable used according to the invoice, was 6mm DC cable. Would that affect the amount of amps coming through to the inverter? I have felt the cable before as it comes into the fuse, and it is warmish. Not hot by any means, but definitely warm to the touch so that it is noticable.

So I have a crappy pwm 3kva/3000w inverter. 24 v. I have two Allgrand 200a/h 12v batteries connected to the inverter in series. The inverter is set to ONLY charge the batteries from solar power. The inverter is also set to switch to the grid/utility supply should the solar panels no longer be providing any current. So at night I am on utility. Because they are gel batteries, my thinking is to not "waste" cycles for night usage when the grid is available. The inverter however will switch to the batteries should the grid go down at night. I do not have a separate battery monitoring/management system connected to the inverter so cannot accurately tell state of charge. I don't even know if my inverter supports connecting one? So here is my problem....what to set the various voltages for charging and low DC cut-off on the inverter. Bulk charging voltage (C.V voltage): Default is 28.2, I raised it to 28.4 Float charging voltage: Default is 27.0, I raised it to 27.2 Low DC cut off battery voltage setting: Default is 20.4 which I think is ridiculous and cause damage to the battery, so I set it to 24.0 which is the maximum Battery stop discharging voltage when grid is available: Default is 23.0 which I again thought was too low, so raised it to 24.5 Battery stop charging voltage when grid is available: default is 27.0 and I raised this to 27.2 to match the float voltage in (2) above. I have attached the spec sheet to the battery that I got off the net. GEL Battery 6CNFJ200 12V200Ah.pdf

Unfortunately the whole solar industry (in Bloemfontein anyway) is just FILLED with this type of dishonesty. They are screwing people over left and right.

Mine is rated at 50AMP @ 30V which amounts to 1500w it should in theory be able to handle from panels. I have seen it on very rare occasions jump to 44amps for a few minutes without issue so I think it can handle at least the rated 50 amps. Highest I have seen its voltage is about 28.5 or thereabout. So I think it can get close to 1500w in terms of amps, just not in terms of voltage. And I think it would need about 2200w worth of panels to do it.

Installer told me the MPTT inverters break easily and many have been returned to the supplier, and the supplier recommends the PWM one because they havent had a single return. He also promised me the difference in performance wouldnt be that big. *insert foot in mouth emoji* I now realise the PWM probably wasn't selling, hence selling them to idiots like me.

I am generally the same. I try to do my research as best I can. But sometimes that information contradicts what the experts tell you in reality (just as an example, every expert will tell you that you never skimp on tyres. I try to buy the cheapest tyres I can (from reputable dealers who wont sell "chinese crap") and in 15 years of buying my own tyres since owning a vehicle of which I now have 3, I have never ever had a single tyre failure due to quality). I have a pretty good relationship with the electrician that did the work. He is a good electrician, but clearly isnt clued up on solar despite having done MANY installations. So yeah, like I said, I will get hands on and try to sort out the problems myself as best I can.

With all due respect, I thought it was someone professional that did the installation. And that is the reason I have been so hesitant to do this for so long. All the "professionals" out there. Will try my best to sort out the issues myself as best I can. The rest will just have to stay non-compliant until I have school fees to spare again.

So it seems it has to do with the inefficiency of a PWM inverter. Tested yesterday, by connecting 3 panels only (out of the total of 6). Put at least 1500w of load on the system, and the 3 panels produced 590-600w (25v and 24amps) which makes sort of sense as the panels are rated at about 8 amp each. So the amp rating makes sense as panels are in parallel (the voltage is very low from the rated voltage of about 31V the panels are supposed to provide). Then did the same experiment with the other 3 panels. Same exact result. However when all 6 are connected, I get about 1000w total from the panels (higher volts at about 27-28 but not double the amps or even close to double the amps at about 37-38). Lesson learn. School fees paid I suppose. Only good thing about this is that I am learning. And am in the solar thing now with zero debt. All paid for cash. Wouldve pissed me off if my R150k system I took a loan to get was doing this LOL.

Correct on all accounts. No surge protector on the solar panels. Also no earthing on the solar panels as far as I know.

Stupid question, but I dont have a breaker, but only one of those glass fuses that fits into a breaker type housing. So I remove the fuse, disconnect all but one, then put the fuse back in. Repeat.

Based on the amps the panels should be producing, I have always been of the suspicion that one panel just isnt working.

Thanks for this. More school fees to pay I guess. I definitely do not have another fuse close to the panels either. Only a fuse in the AC DB board for the solar panels. No fuse from battery to inverter. AC and DC sharing same conduits.

I think this is what I have installed Spec sheet

Another quick question(s).....am I correct to assume the following: 1. There MUST be a fuse between battery and inverter? 2. The DC cabling from the solar panels should not share a conduit with the AC cables? And thus, the solar panel fuse should not be located in the same DB as the home's DB (the AC DB)?

I am a noob at this and by no means even slightly an expert so please keep that in mind and please ask for any info I have failed to provide for you to help me solve this issue. I have a 3kva/3000w Synergi PWM (yes PWM not MPPT) 24 volt (yes twenty four volt) inverter installed. Connected to this, I have two 12 volt 200 amp/hour AllGrand gel batteries installed in series. I then also have six 270w Enersol solar panels installed in parallel (this is how the manual says the panels should be installed). Now here is my problem. This should be producing a theoretical maximum of 1620w, but only ever does a maximum of 1000w and averages in the 800-900w region. Accoring to the inverter display, it does this at around 25-27volts and 36-40amps. Basically I am losing around 40% of theoretical solar power. Roof is north facing. Not sure of the angle of the roof, but it is a "standard" angle of what I estimate to be about 30-40 degrees slope. I am at work now, but will happily provide pictures or whatever else info I have missed when I get home after work. Installer blames the fact that it is a PWM inverter and not MPPT. Same guy also promised at least 1200w of solar production, so go figure.

Also interested. Would like to know more specifically how the Pylon Tech batteries are holding up.

So it seems Major-Tech are pretty crappy. Source Mechanical life is only 10000. So half of CBI and a quarter of Hager.

Yes sir. Same stuff to the best I can get them to be transparent as one doesnt list the specific equipment being supplied merely that it is a "victron inverter" (the "15kva" is the heading of the quote so I assume its a 15kva victron inverter) and that it has 20kw of battery storage and 6.9kwp of sun panels. The 2nd company did provide specifics on what equipment they were supplying but doesnt put prices next to each item. Just the total at the end.

I hear you. I really do and agree 100% with what you are saying. But going smaller wont negate the fact that I will still ripped off by Bloemfontein suppliers. I will be charged R200k for a R100k system.

So it seems solar isnt in my future. Received two quotes from local suppliers in Bloem. R377k including some installation costs from one and R281k from another excluding installation. Compared to the quote I got from a JHB company for the equipment of R224k I can see that we in Bloem are just being ripped off when it comes to solar. Would love to use the JHB supplier, but not willing to take the risks of purchasing such expensive equipment from a supplier so far away. Also not willing to be ripped off from the local suppliers. So I suppose a solar geyser it is then to save on electricity. At least that I can get sourced and installed from local suppliers/plumbers in Bloem for the same prices as other cities.

Yip. Literally close to boiling as it easily burns the skin.

Colleague has the water running down the roof problem. His solution is that twice a year he has to get on the roof and use shadenet to cover a portion of his tubes so the water doesnt get too hot. In winter he has less covered than in summer.