I have three sections in my DB. Two of the sections have auto-changeover switches. It can switch between inverter and Eskom. The third section in non essential straight from Eskom like dishwasher, tumble drier, underfloor heating, geysers, microwave and my kettle plug.

1st automatic changeover switch is for essentials like CCTV, lights, Alarm, gate motor, tv plug. These run 24/7 on inverter backup.

2nd auto changeover switch feed the rest of plugs for Fridges, TV’s, computers etc. Normally switches on at 7h30 till 15h00 when daylight and with PV availability.

This is how my Axpert worked for more than two years , now I replaced the Axpert with a Sunsynk but C/O switches still in place and the Sunsynk with all it's features don’t really need the second changeover switch as it can feed back to non-essentials as well, but if Eskom is down it cannot, for that reason I think it’s worth keeping the second changeover as I can still switch the second lot of loads over to inverter if needed in long power outages. 

I have one other separate change over installed that also work with a sonoff to switch my one geyser between eskom or solar PV during daytime peaks to try get max out of the system. 

What would recommendations be about this setup unnecessary or does it have some merit?

I would say to leave the second change over switch so that those loads get permanently powered from the grid, just because I'm not a fan of switching power on and off daily to any equipment. In the event of an abnormal loss of power like power cables being stolen or transformers blowing up and such you can easily just power those loads from the solar.

Hi Gerrie,

Quick one - 

 

You mentioned this

"2nd auto changeover switch feed the rest of plugs for Fridges, TV’s, computers etc. Normally switches on at 7h30 till 15h00 when daylight and with PV availability."

Do you manually switch over and back at those times? Or is there some timer involved? I'm just curious how to accomplish something similar that is timer based, specifically on changeover from and to grid.

1 hour ago, JoeyhZA said:

Do you manually switch over and back at those times?

Hi Joey this is timer based with the Sonoff switch fitted inside my DB. When weather is nice I just leave it to switch with timer settings on my phone, but when the the weather is cloudy I just disable the timer on my phone. The screenshot below is the two change-over controls.

11 hours ago, De0n19 said:

I would say to leave the second change over switch so that those loads get permanently powered from the grid

I’m still new with Sunsynk but the second change-over might be worth it due to me only having one Pylontech US3000 battery, if I had more batteries I could possibly go completely off grid and would not need that second switch, but with one battery I need to keep my loads according to battery capacity.

My electrician installed sunsynk as a ups at my office but he says when grid is down I need to manually switch to the battery power. This does not make sense as I wanted UPS esp when I’m not there to change over.  Any thoughts 

On 2022/06/17 at 6:42 AM, DonG said:

My electrician installed sunsynk as a ups at my office but he says when grid is down I need to manually switch to the battery power. This does not make sense as I wanted UPS esp when I’m not there to change over.  Any thoughts 

You could leave the changeover on inverter backup permanently and see what happens. Is your inverter wired only for essential loads or for your entire DB loads, because if your inverter is too small for all your loads it can be a reason why he said you need to manually switch over. Normally the DB needs to be split to essential and non-essentials, if this was done you shouldn't need to switch manually.