GreenMan

Two things you would need IMO to successfully use a generator are:- A decent waveform from the generator which an inverter generator would give you as mentioned earlier in this post. We put a decent generator, a Honda with AVR on the oscilloscope and the waveform was horrendous - so bad that the APC UPS would stay on battery. Make absolutely sure that you limit the power you will draw from the generator to a fair amount below what the generator specs are. Remember that if you are at altitude you need to de-rate the power output. If your solar inverter overloads the inverter gen then it will trip. Also, not flogging the engine and inverter to death will hopefully ensure a decent life from the generator. Unfortunately the inverter generators are available in small to mid sized power ratings only. They are also more expensive per kVA or kW compared to normal gennies as they are more complex. It uses the petrol engine to make DC and the DC is fed to an inverter (hence the name inverter generator) to make nice clean AC which your solar inverter will be happy with.

Yes to put it in the DB board directly would make it neat - also noting that one can purchase a Sonoff box with DIN mount. This contactor would work for geyser as it has 25A contacts. And....it is DIN rail mounted. Price is not too bad at R156 incl VAT. It looks like it breaks both L and N and I think the Sonoff only breaks the Neutral but am open to correction. https://www.robotics.org.za/CT1-25

@Roadkill can you post the name of the installer in order to warn others ? As YellowTM says, at a loss for words at your poor treatment and the bull that you were told.

Great ! I look forward to them arriving...

@Gordon, the clip comes with the adapter

Yes they do in terms of vertical alignment and flush with other CBs. If the DIN breaker is shorter than the hole in the DB board lid the adapter comes with a plastic clip that mounts on the DB board lid to block the gap to make it safe.

FYI If anyone in GP land is looking for the Astutes I saw about 6x units at Builders Warehouse Edenvale yesterday. R349 each. I hear that they will be coming out with a plug-into-wall-socket version in the near future - I have asked for an ETA as will be easier to use for a single appliance eg a dishwasher.

I used these Product Individual – ACDC Dynamics Online http://a365.acdc.co.za/Images/acdc-web-images/ima1/CK-SAM.JPG Works well.

Sold !

I pushed the "Like" button for your pre-charge arrangement. Your setup was a bit easier as you only have 1x fuse.

Paul Are you using Vox as your ISP with their router ?

QB For interest sake, now that you have opened the battery, is the battery in that Dyness a 15S or 16S ? Are they using pouch cells ?

Yes pretty much so but you would probably struggle to find an off the shelf 96 V secondary. So your best option is to get them wound for you. You could try SJ Andrews [email protected] Your first post mentioned 320W so this is a motor application so we can assume PF of 0.8 so that would equate to a 400VA transformer. The MPPT voltage rating that you require will depend on the max voltage you will get out of the secondary side of the transformer. Does the spec sheet state what the max voltage is that you will get ? I assume you would put a bridge rectifier on the secondary of each of the transformers ? Did they supply you with a schematic diagram that you could post ?

OK that information is useful. So it appears the generator phase to phase voltage is 208VAC. This works out to a voltage of 120V per phase to the neutral (star point). So you do need 120V input to the transformers. Good news is that you dont need to worry about getting a transformer specially wound for 117/24 volts. A transformer that has primary voltage of 240V with 2x 48V secondaries (wired in series) should work well. It is perfectly fine to drive a transformer at 1/2 the design voltage. In other words a 240/96 transformer driven by you generator will then give you 120/48 which is the transformer you were looking for. I reckon they show the option on the secondary as 24V or 48V so you could have a 24 or 48V battery pack in the system. It does not matter if you run the transformer at 50 or 60 Hz according to the pdf you posted. I would suggest you oversize the transformer to minimize losses and lessen the voltage drop across the windings.

Does the generator produce 117V or 234V ? (or the more normal 120V or 240V). From the pdf you sent, the transformer can be wired in series for 234V or paralleled for 117V. If your generator is 234V then you don't need the 117V windings and just need a single 234V winding. I presume you would need the 48VAC output of the transformers. You DONT need to get toroidal transformers - normal transformers will work fine. I agree with Kalahari Kat that you will need a (preferably MPPT) charge controller to manage charging parameters such as charge current and voltage so that you don't damage your batteries from overcharging. Because you are producing DC from AC you might need to put some smoothing capacitors in - but I am not sure of that.

I think the fact that it does not mention true-sine wave means that your unit is a modified sine-wave design. A sure way to check is to get one of your tech savvy friends with an oscilloscope to check the waveform on the output of the UPS (using a suitable step down transformer). Picture from https://www.nytimes.com/wirecutter/reviews/the-best-gear-for-your-road-trip/

First guess. That inverter is not a true sine wave inverter but a modified sine wave inverter. So the UPS does not like the modified sine wave it is receiving and thus stays on battery... Do you have a technical data sheet or spec sheet for that inverter ?

Hey Iceman There are a number of options to replace those ridiculously priced 2.5AH 12V batteries. Cheapest and easiest is to simply replace them with 3x 7AH Sealer Lead Acid batteries. This will provide you with plenty of capacity and the batteries are cheap as chips (get decent brand ones eg CSB or Forbatt). The existing charger may be a little under rated but the effect is not too serious as the charge time will take longer if the batteries are really flat. Simple job to put the new batteries in an external case as I am sure they are not likely to fit where the old ones went. Check if you can find the charging circuit IC eg LM317 and if it does not have a heatsink, put one on ! LBSA sell 6 AH 32700 cells and a 36V BMS (12S). The 32700s have built in nuts and bolts which make it easy to assemble with connecting strips. This is a neat and elegant solution. Cells - https://lithiumbatteriessa.co.za/collections/cells/products/3-2v-6ah-lifepo4-lithium-ion-phosphate-battery-call; 20A BMS - https://lithiumbatteriessa.co.za/collections/bms/products/lbsa-bms-20a-12s-36v-lifepo4-lithium-ion-phosphate?variant=34759461503143. Cell connectors - https://lithiumbatteriessa.co.za/collections/diy/products/battery-connector-set. If you want to go down the 18650 route (I built a 10 AH eBike battery with them) you will need a 10S BMS. Have not found one locally available though. I imported mine from AliExpress. I soldered the connections between the 18650s but the result is not very pretty so I have ordered a spot welder to connect the cells using nickel strip. PS make sure your reclaimed 18650s in the pack you are building are of similar capacity and I would highly recommend you also check that their internal resistance is acceptable. You can get a charger that has a built in internal resistance checker or you can do it the manual method - google it and there a number of good sites describing how to do it.

Where are you based sir ?

Johan PM me your email address and I will email to you.

I concur with Gnome and Calvin. The King definitely does blend the PV and AC incoming. It is one of the reasons I went for the King. I was a bit dubious if the King could do this blending and.... sadly there was no definite information on this on the internet. One of the first things I did when I installed it was to test and confirm that it could indeed do this blend of AC and grid. I added a Victron BMV to my Pi running ICC and now I get much more accurate SOC information and, in my opinion, the BMV is a must-have. My biggest gripe with the King is the max 145 VOC which means more cabling...

Hi IOPS First dibs please...

Had situation at site where the UPSs for the individual PCs cycled on and off while on the generator. This happened for good few minutes until the (brand new) batteries were flat Some UPS were decent APC brand. It was a Honda generator so had no doubts about AC waveform quality.... until we put a scope on the 220V inverter output. We saw that the output waveform was severely distorted and that is why the UPSs kept kicking in ! This was a surprise as one assumes that the generator output will be a beautiful/clean sine wave ! Finally, I read somewhere that the generator output is recommended to be 1.5x the rated power of the inverters...

Sven Something to check:- Is your water and electricity bill drastically higher than previous months ? We did a repair job at a retirement village with 2x 200 litre geysers in parallel and they had NO hot water. Checked all the usual - solar controller working; pump working(this case an AC pump); no air lock etc etc. After much investigation we found that there was a big leak in the geysers hot water pipe underground that was not physically visible. So the water never stayed in the geysers long enough to get heated by solar and also the heating elements were on for half the day as backup heating. Fixed leak and problem solved. Needless to say, their water and electricity bill was substantially higher than normal. Also the old folk did not have hot water....