Tony Swash

Duh just seen the setting

Hi all, I have a spare Axpert MKS 5kva that I want to install as a UPS no PV input. I have done many Axperts with PV. Is there a clever way to set up the inverter so that its in bypass mode charging batteries and switches over when load shedding occurs? Rgds Tony

Make sense to me, many thanks

Hi all, I could do with a technical response for my question please. The moment the inverter is connected in parallel with the grid, it does synchronize with the grid for load purposes. Then it is an Embedded generator. Is this statement correct? I cant seem to find a suitable response to say if it does or doesn't. If anyone has a line diagram and description it would be very welcome. Rgds Tony

Many thanks to both of you. The Langeberg Municipality are engaging with installers and homeowners alike to bring some resolution, so that all parties are happy.

Here is the definition of the spec 1. Inverter have to be an off-grid inverter, and not have the function to feedback (not an bi directional inverter) 2. Off grid diagram attached as per our requirements. 3. Declaration form completed. (Attached) 4. Electrical certificate of compliance (COC) for the installation. 5. Comply to all the following definitions: “Off-grid/ Stand-alone generator/Off-grid generator” A generator that is physically separated and electrically isolated from, and can never be connected to the utility’s electrical grid-either directly or through a customer’s internal wiring. The consumer’s loads cannot be simultaneously connected to the utility grid and the off-grid generator. Export of energy into the utility’s grid by the generator is therefore not possible. A generator that is connected to the grid or to the customer’s internal wiring through a reverse flow blocking relay is not considered to be Off-grid, but rather as an EG.

My next question would be that if it is bi-directional then which inverters will meet the councils spec. The council will only allow an installation if the inverter can not physically feed back to the grid endangering people working on the grid. A fully compliant system is allowed up to 60% of the households incoming limit ie 3kW. However if the system is deemed to be off grid then one can add unlimited inverter power. However in of grid mode the inverter must be totally isolated from any AC input via a change over switch. Unfortunately this means that the inverter has no means of a bypass supply in the event of low battery or overload.

Hi all, Could anyone please confirm whether an Axpert MKS (or other derivative) is a non- bidirectional inverter. If so, how does one prove this. I have attached a drawing supplied by our local municipality as to the allowable spec for an off grid inverter install with a PV array. Any assistance guidance on how to confirm this in writing would be extremely welcome. Rgds Tony

Thank you guys for the response. I have attached a sample drawing that I received from the local authority. “Passive standby UPS utilized as an off-grid hybrid generator” Apply to any UPS operation functioning according to the following principle: a. The normal mode of operation consists of supplying the load from the grid as a primary power source. b. When the primary source/grid is not available, the load is supplied from the UPS inverter operated in stored-energy mode. Such a system is regarded as off-grid provided that it is equipped with a suitable mechanical change-over switch, selectable as follows: 1. Charger/rectifier mode (normal): Batteries are charged by the grid/Solar Pv panels. The grid is the primary source for all the loads, or, 2. Inverter mode (when the grid supply is interrupted or unavailable). The grid supply is disconnected and selected loads are supplied from the inverter, within the rating of the energy storage or Solar Pv panels.

Hi all, Excuse my ignorance if this question has been asked and answered before but I am interested in how the term "off grid" is determined. Our local municipal guidelines state that 3.10 Off Grid System Stand alone generators (not connected to the municipal electrical grid in any way) do not need permission from the electrical department to install. If my understanding of the Axpert model inverter/UPS is that when it is supplying AC to your DB it isolates itself completely from any incoming mains AC supply. To go further than that. If it is installed without any AC connection at all then it is not physically able to connect to the AC mains. Therefore is it now an off grid installation or was it off grid all along? Personally I would argue that the inverter portion is completely separated from the mains supply, making it off grid. This is very important as we all want to comply with the local authorities but how do you prove this point to them? Your informed comments are most welcome.

Hi all, Excuse my ignorance if this question has been asked and answered before but I am interested in how the term "off grid" is determined. Our local municipal guidelines state that 3.10 Off Grid System Stand alone generators (not connected to the municipal electrical grid in any way) do not need permission from the electrical department to install. If my understanding of the Axpert model inverter/UPS is that when it is supplying AC to your DB it isolates itself completely from any incoming mains AC supply. To go further than that. If it is installed without any AC connection at all then it is not physically able to connect to the AC mains. Therefore is it now an off grid installation or was it off grid all along? Personally I would argue that the inverter portion is completely separated from the mains supply, making it off grid. This is very important as we all want to comply with the local authorities but how do you prove this point to them? Your informed comments are most welcome.

Many thanks, a lot of people are asking as the price difference is enormous

Hi all, Can anyone advise on the following. Can you install the Dyness B4850 in parallel with the Pylontech 2000 or will the BMS's clash? Rgds Tony

Hi all, I have an Axpert 4k being fed by two arrays and charging two 7.4kWh Solar MD lithium batteries. Between approx 10h50 and 12h30 the Axpert shows the PV array giving 2.45 to 2.65 kW charge and staying there. If I disconnect an array and then reconnect, the Axpert shows 3.74kW being 2.3kW from one array and 1.44kW from the other. The batteries are at 68%. The inverter then carries on happily all day and the batteries are 100% by 14h00. We then irrigate and heat water until 17h00 using the panels leaving the batteries fully charged. This happens every day. The inverter was in parallel and connected to the low power array so this was not noticed. Now we are back to one inverter. The inverter uses a Solar MD data logger and for a while it was running under Ai control. The guys at Solar MD tried all sorts of settings but to no avail so now we are back to normal. Charge setting is 80A. Has anyone seen this type of behaviour before. My previous RCT Axpert was connected like this for two years and never had this problem.

Thanks, I did a pin out check and they are all ok and one to one, as is the OEM cable, so still confused. Will have to get an OEM somewhere.