pilotfish

Nowhere does @Bere say that he has a suitable structure to house the inverter/batteries at the remote location, only that this is where full sun is available. So are you all advocating that he slap up a building to house this equipment when he has already mentioned his restricted budget, rather than accept a MAX 4% DC loss, which he could reduce to MAX 2% by doubling up on the 35mm cores? If we ever get to have a lunch then you lot can split the bill, because you seem to be impervious to cash constraints

The current rating of a 35mm x4 armoured cable is: In ground 143amps Enclosed Duct 116amps Free Air 135amps So you should be OK.

Hi @Bere There is 2 ways that you could go about this; Option 1: Install panels/inverter/batteries at the remote location if suitable structure is available for the inverter and batteries, then use the 35mm cable (L + N + earth + spare) to transmit AC to the house (your AC volt drop will be negligible over the 35mm cable). Option 2: Install only the panels at the remote location, and transmit the DC power over the 35mm x4 cable to the inverter/batteries located at the house. I prefer this option as you may need to interface with your inverter regularly in an Off-Grid situation, and you will need to be quite fit if it is 100m away! If you go for option 2 I would recommend the following; I believe that your panels have an Open Circuit voltage of your panels [Voc = 38.3], that being the case I recommend that you use a 3s4p arrangement [4 parallel strings of 3 panels in series]. That will give an open circuit voltage of 115V which is well within the 145V maximum voltage for your inverter. At a Imp [max power current] of 9amps you can expect a maximum current of 4x9 = 36 amps. The 35mm cable has an impedance of about 0.6ohms/km, so using just 2 core [red+ / blk-] your cable resistance would be about 0.12ohms giving a volt drop of 4.32or about 4%. You could either accept this 4% drop, or double up on the 35mm cable [Red,Wht+ || Blk,Blu-], which will put you below 3% voltage drop. Personally I would use a single pair and accept the 4% drop, and then use the other pair to carry generator power and locate the generator at the panels (generator noise drives me nuts!). Just dont ever tell anyone that I suggested using a common cable for AC and DC. Use the armouring for earth back to a common earth point near the house, and please put surge arrestors on the house side of the cable (DC arrestors for the PV supply and AC arrestors for the Gen supply if used) as the 100m long lightning enticer could cause you ongoing problems. Remember that surge protection is only effective with a good quality earth. As soon as the budget allows add 2x HA02 battery balancers (4 batteries per HA-02), after that add the Victron BMV-702 and ICC control software (search this site for detailed info). The Axpert battery management is pretty dodgy, and these items will go a long way towards maximizing battery life. Good Luck with the install.

Sounds like faulty/damaged battery.

What is the battery voltage, what type of clamp meter (plenty clamp meter cant measure DC amps).

Thick as your thumb? your arm? your leg? Sorry - its late on Sunday after a tough weekend. To offer an opinion we would need better info - when you say 3 phase is it a 3core or a 4core cable? is there a separate earth? Do you know what size the cores are (4mm/6mm/10mm/16mm/bigger)? is it an armoured cable or some other type?

Sure, I will give you R5000 and keep it as a backup if it is MKS 5k version (mppt not PWM) and still 100% functional.

I prefer to use the term "Grid Assisted" where grid power is used as backup and "Off-Grid" where no grid is available or used. The reason for differentiating is that design requirements can be very different for the 2 options - An "Off-Grid" system would normally have a battery bank offering a couple of days autonomy to minimize reliance on a generator, whereas a "grid assisted" systems can have a battery bank ranging from similar to that above down to a minimalist battery bank, using PV when available and grid when not, with battery just there to carry through the transition.

Some type of AI robot???

Same here, fair price and great service from @Chris-R.

They have a similar option... PC Browser - if you do any kind of item search then a filter option opens on the left, go to [ITEM LOCATION] and tick [South Africa], all drop shippers are now history. Android App - the filter appears in the search window after you have entered search criteria.

Marketing materiel (10 - 15 year life with 36mnth warranty) and price seem good, If you can get hold of a data sheet for the batteries please post it here.

Are all the batteries the same age? I wouldn't mix 3 year old batteries with new batteries, you will wind up killing your new batt's very quickly. If you plan on using just the good string of batt's in the mean time until the budget improves then this is a viable option. This would be a good solution (but see below) - but you should add an HA-02 battery balancer. The damaged string in the old bank probably came about as a result of 1 battery going "out of sync" which resulted in the other batteries needing to pick up the slack and failing as a result. The HA-02 will help to prevent this from happening to the new batteries. 4 x 320w panels is a good balance for 4x 100Ah batteries but is not enough for 4x 200Ah batteries. Your 1280W PV array will produce around 6kWh on a good day and who knows what on a bad day. Your 4x 200Ah batts can theoretically supply about 10kWh at 100% discharge or about 5kWh at 50% discharge (which you should try not to exceed). 5kWh at an estimated 85% charge efficiency will require the full 6kWh provided by the panel to fully recharge the batteries, leaving nothing available for direct consumption. In practice the Axpert will supply loads directly as required during the day meaning that there is not enough capacity available to properly recharge the batteries. Leaving batteries partially charged on a consistent basis will lead to sulphation and premature failure. This is also a very likely contributor to the original battery failure. So the sad truth is that if you plan to go back to a 200Ah battery bank then I would recommend doubling the size of your PV array. The budget for this project (DIY) should be around R30k.

I have used the dude before and he is reliable.

https://www.bidorbuy.co.za/item/325759559/Voltmeter_Digital_Red_0_30V_DC_IN_STOCK.html Self voltage measurement = 4.5-30 VDC Seperatel supply measurement = 0-30 VDC The same supplier has other 0-100 VDC (and 0-50ADC) that will require isolated supply which can be accomplished by using small cheap(ish) DC-DC converter.

Seems TTT may be admitting that he is addicted to being beaten by his wife, Is this a 4th personality rearing it's head???

Sorry I used the incorrect term, I was referring to the charge settings (program 16) where I recommend [OSO] only solar for a grid assisted system, whereas an off grid system should be set to [Cut] to facilitate charging by generator. The reason i recommend this setting is because charging batteries is not 100% efficient and so should be done with free PV power and not costly grid power - this is easy to do if you have reliable grid available. Program 1 should be [Sbu] and not [SOL], apologies for any confusion created.

If you are using 6 panels in series to create 1500w and 220v then you should use a 1500w element and there is no reason not to work, but how will you control the temperature? - if you put 220v DC on your normal geyser thermostat then please DONT tell your insurance broker what you did when the house burns down!!! You will need a suitable (read heavy duty and very expensive) DC relay to switch the power when the geyser reaches temp - you could use the normal thermostat to control the relay.

If you add more intelligent control to your system then I think your will be able to accomplish what you ask above; Hook up a PC or RasPi and install ICC software to monitor and control the Axpert system, Add a Victron BMV to monitor the battery state of charge correctly, Set the battery charge to SOL (solar only), In ICC go to Axpert Settings and set [To Grid SOC = 75%] and [To Solar SOC = 90%] If you do the above then in the morning your home will run on grid until the batteries reach 90% SOC (probably around 9 > 10am) and then switch to solar, on sunny day your system will continue to use solar and charge the batteries to 100% if excess PV available (use heavy loads between 9am and 3pm). At night you will run off battery until you reach 75% SOC then switch to grid untill your batteries next reach 90%.

...which takes you back to the Geyserwise system which has a DC element and DC/DC converter (MPPT), but with the added intelligence of the Geyserwise controller which will control DC/DC converter by switching off when the water reaches temp (have you looked for a relay that will switch 48v/20amp DC?) and allow your 230v backup to heat the water at programmable times if necessary. I have a Geyserwise (solar-thermal) and a Geyserwise (PV) on separate geysers and I must say that the solar-thermal system delivers much better results.

I am trying to wrap my head around how this would work... The Geyserwise PV system works in conjunction with an MPPT produced for them by Microcaire which outputs 48v onto their DC element which is normally around 900w, so about 19A DC when sufficient PV power is available. If you have a 150L 3kW geyser and didn't change the element this element would have a resistance of around 3000/230 = 13ohms, connecting a 48v DC current to this element would result in about 3.7amps and a power of about 180W...?

No problem, have your laughs... I have a 10kVA inverter with 6.2kWp and 120A charging capacity that cost me R15k, I can afford a few giggles at my expense! PS - Inverter cost only for 2 MKS5k in parralel, the rest of the stuff cost an arm+

I dont know this system but having glanced through the website there is no reason that I can think of for it not to work. PV panels feeding an inverter with grid backup - output to the geyser - no problem. Geyserwise do a system which I have used successfully, but Geyserwise uses a Titanium DC element whereas the Geyserworx system uses a standard AC element and so any geyser could be retro-fitted without the need for plumbing. It would basically boil down to the cost of the system and Return on Investment.

Go to this page; http://forums.aeva.asn.au/viewtopic.php?t=4332 and read thru the firmware section.

...and then a cloud came past... Batteries are required for stability of supply when supplying a load from an inverter, just because it can be done without batteries doesn't make it a smart idea.