TonyH

There is a lot of confusion. I belong to a Body Corporate which is ESKOM's customer. I am not a customer. The SSEG registration is for an existing ESKOM customer or a new ESKOM customer. The municipality in the area is no help.

https://ecasa.co.za/technical/neutral-earth-bonding-clarified/ Here are the clear regulations. A bonding relay is required in islanding mode. The Neutral output from the inverter is pulled down to earth through the relay to an earth spike. People who say that the relay can fail forget that the eskom earth cable can be stolen or disconnected for some reason. The earth bond installation at your inverter must be according to regulations that is the installers responsibility. The Eskom earth is eskom's responsibility.

Here is a solution:

The battery 48VDC is converted to 220VAC by the inverter. The 220VAC Neutral on the output is isolated from the Grid during islanding. Normally the neutral is connected to earth in the substation. That is why the neutral floats in reference to earth. Hence anti islanding needs to be installed to pull the neutral down to earth potential.

South African regulations forbid connecting the Inverter output neutral to the earth permanently. No power generator may connect the output neutral to ESKOM neutral permanently. Some inverters like Sunsynk have terminals that can drive a relay when on islanding mode. The relay then connects the Inverter output neutral to an earth spike and house earth. Other inverters connect the inverter output neutral to earth internally. The manuals should provide that information. If an inverter doesn't have terminals to drive a relay or internal neutral bonding then a relay can be installed as shown below.

Anti Islanding to ground the neutral when the grid fails or is off. If the Inverter you have doesn't have a contact that gives 220VAC when the grid falls away one can use the normally Closed contact with the live connected. A time delay on relay should be used to allow the inverter to synchronise. Each inverter is different in the time it takes to switch back to the grid after the grid powers up.

If you have a Sunsynk inverter use the aux output to charge your geyser as soon as the batteries SOC is 100%. This is a great way to get your thirsty geyser away from the rest of the house. On bad days it is simple to switch on the aux and use the grid. Remember to put in a EL and double pole isolator.

Hi, here is my as build

I suspect that there were no comms. When you connect try the CAN BUS comms port. If it is working you will see it on the LI BMS selection.

Hi, the SunsynK inverter has an Aux output which you can use to charge the geyser after the batteries are 100% SOC. Remember to put an earth leakage into the circuit to the geyser. This is useful if the batteries do reach 100% SOC around the middle of the day.

Have you got comms? The comms are usually setup for CAN BUS and the cable put into the CAN bus input.

Hi, I had the same problem. I had connected the comms cable to the 485 input instead of the CAN Bus input.

I have used he auxiliary to heat the geyser for a year with no problems.

Hi, the Sunsynk inverter has a table that will ensure that the SOC never goes below the level at any specified times.

Hi, are you aware that the auxiliary can be used to charge your geyser when the batteries are 100%. It works very well. Just remember to place an earth leakage as well as an isolator for safety reasons. It is very easy to heat the geyser from the gril in rainy or overcast weather if you need to.