Hi there. I hope someone can advise me on how to prevent my battery invertor system from feeding power back into the mains grid.

I live in a small house in the lowveld bush. I run my geyser and stove on gas and only require my backup system to provide power for fridge and lights and a couple of other low draw items.

My DB is a small unit with only 3 circuits - lights, plugs and outbuildings with an earth leakage unit.

I know I should use an electrician to install the system for me, but there is no one locally available, so I'll wire it myself and get someone to check it later.

I have checked the whole system and it works perfectly, but my problem is how to stop the system from feeding back into the mains grid when it is on battery.

I know I could manually switch it, but I need it to switch automatically as I am often away for a few days and there would be no one here to switch it. Also my mains switch is outside in the bush and I don't want to have to traipse out there every time the power goes off or on!

I want the batteries to feed both plugs and light circuits. Can anyone advise how best to do this?

Thanks!

 

What inverter do you have? Has it got an auto change over switch built in?

  

If it does not have the change over switch, then something like this should work.

Switches - Loadshedding Power Failure Auto Backup Power Change Over Switch 2 x Relay 220V 10A **LOCAL STOCK** for sale in Cape Town (ID:589299981) (bobshop.co.za)

 

Hi GVC - It is a 3kVa MUST invertor and it does have auto changeover built in.

If you want your entire DB on inverter, connect the mains incomer to inverter input and the output to your circuits. Or only connect the output to those circuits that you want on backup power. (you must obviously remove the current grid supply wire / busbar to the circuits and only run them on inverter output)

You will have no feedback into the grid.

Such a simple solution, why could I not have thought of that!

Excellent, thank you!!