Hi

I am thinking of going for a SunSynk 8kw inverter system. Here is my setup, I have a main house and a granny flat with combined usage of +_ 32Kwh per day. What I wanted to try and do is this.

1) Main house essential loads must run off solar first priority, second off battery(load shedding and at night) and lastly if grid available off grid if solar not enough or batteries flat.

2) Main house non-essential loads must run off solar if available after essential loads, then run off grid if not enough solar (would like an option to maybe change to battery in an emergency)

3) Granny flat first prize would be to run off solar if enough solar, then grid if not enough solar, then this is the catch, if load shedding I would like to only run lights and maybe some plugs. Problem with last part is the granny flat is fed off from the main DB with a 63 amp breaker to its own DB after a prepaid meter.

 

How would the granny flat be "connected" to the inverter as a non essential load, then how would I run the granny flat off batteries without running the house non essentials on batteries. Would it be possible to us the AUX port for something like this.

From what I've seen here and elsewhere the Aux port is difficult to get right.  8kW goes a long way - I have 8kW Deye and after toying with smart load (Aux) a couple of days decided to put everything except my oven (gas hob) after the inverter.  I schedule my geysers to run at times of maximum solar production and can drop the temps on the Geyserwise panels or flick the switches in the DB if there is a prolonged outage.  This setup works for us. 

Edited February 7, 20223 yr by Scubadude

20 minutes ago, Scubadude said:

From what I've seen here and elsewhere the Aux port is difficult to get right.  8kW goes a long way - I have 8kW Deye and after toying with smart load (Aux) a couple of days decided to put everything except my oven (gas hob) after the inverter.  I schedule my geysers to run at times of maximum solar production and can drop the temps on the Geyserwise panels or flick the switches in the DB if there is a prolonged outage.  This setup works for us. 

Thanks Scubadude

 

Was also think to try and keep it as simple as possible. Just the granny flay is causing me to over think this. Other idea was to run a "second" cable to the granny flat from the main DB that we connect only a lamp and a TV to just for load shedding??

So point 1 is easy, the inverter can be setup for this.

Point 2, also easy until you want to use battery for non-essentials. My understanding is that this won't work. Also keep in mind even if you have excess solar, if the grid fails then everything on the non-essentials side goes off.

My solution was to put everything on essential side and then use Home Assistant, smart switches and automations to decide when to turn things on and off when the grid goes down. That way the big loads still get turned off when grid is down but you can actively manage them and turn them back on manually if you know there is solar & battery capacity.

For Point 3 I would also use smart breakers on the flat DB. So it would also be on your essential side but when grid fails the smart breakers turn everything off other than what you specify. 

You would have to be very careful about total load though with everything on the essential side. 

i toyed around with Smart Load, could never get it to work the way it was designed, anyway it comes out of the total essential load anyway, so, I agree on the 8 kW, you can probably put essentially everything on LOAD

1 hour ago, Greglsh said:

Was also think to try and keep it as simple as possible. Just the granny flay is causing me to over think this. Other idea was to run a "second" cable to the granny flat from the main DB that we connect only a lamp and a TV to just for load shedding??

As long as your CT coil is positioned at the main incommer the granny flat will be solar powered during the day. A "second cable" (is that an extention cord?) is a quick and easy way to give the flat basic power during loadshedding. Of course that would bypass the prepaid meter. 

 

5 hours ago, Scubadude said:

As long as your CT coil is positioned at the main incommer the granny flat will be solar powered during the day. A "second cable" (is that an extention cord?) is a quick and easy way to give the flat basic power during loadshedding. Of course that would bypass the prepaid meter. 

 

Hi, I would run a proper twin flex or 3 core cable that can carry a few hundred watts. Probably bury it and then install a red top plug in the granny flat and label it UPS

1 hour ago, Greglsh said:

Hi, I would run a proper twin flex or 3 core cable that can carry a few hundred watts. Probably bury it and then install a red top plug in the granny flat and label it UPS

Hi Gregish, the best permanent solution would be to run a new cable of at least (1.5mm2 x 2+Earth) it will give you a 15A supply. Than you could fit a small 10way Surface mount DB next to the granny flat DB for essentials only. Just swing the light and the plug circuits over to the new DB and leave geyser and stove if you have those on old non essential DB. It would be legal and not to much trouble to get a C.O.C as well.

 

1 hour ago, Gerrie said:

Hi Gregish, the best permanent solution would be to run a new cable of at least (1.5mm2 x 2+Earth) it will give you a 15A supply. Than you could fit a small 10way Surface mount DB next to the granny flat DB for essentials only. Just swing the light and the plug circuits over to the new DB and leave geyser and stove if you have those on old non essential DB. It would be legal and not to much trouble to get a C.O.C as well.

 

Thanks Gerrie

That does sound like a good plan, do you think the way I was thinking of doing it would not get a COC, I would run the cable in conduit under ground. I think your option is the "best" way to do it. 

12 hours ago, Greglsh said:

Hi

I am thinking of going for a SunSynk 8kw inverter system. Here is my setup, I have a main house and a granny flat with combined usage of +_ 32Kwh per day. What I wanted to try and do is this.

1) Main house essential loads must run off solar first priority, second off battery(load shedding and at night) and lastly if grid available off grid if solar not enough or batteries flat.

2) Main house non-essential loads must run off solar if available after essential loads, then run off grid if not enough solar (would like an option to maybe change to battery in an emergency)

3) Granny flat first prize would be to run off solar if enough solar, then grid if not enough solar, then this is the catch, if load shedding I would like to only run lights and maybe some plugs. Problem with last part is the granny flat is fed off from the main DB with a 63 amp breaker to its own DB after a prepaid meter.

 

How would the granny flat be "connected" to the inverter as a non essential load, then how would I run the granny flat off batteries without running the house non essentials on batteries. Would it be possible to us the AUX port for something like this.

Hi so I have a SunSynk 8k and most of the house is on the essential, except thee oven which i put on thee nonessential load and  I feedback to it while solar is available , how ever I have a Axpert King connected to it with a hubble AM2 to power up the geyser and any nonessential I need and the Axpert is charged with the solar from the Sunsynk.

42 minutes ago, Greglsh said:

That does sound like a good plan, do you think the way I was thinking of doing it would not get a COC, I would run the cable in conduit under ground

It might be possible to get a COC  if labeled correct but it is the kind of thing that will throws red flags to lot of electricians that does C.O.C’s in my opinion a ups plug that is fed from the main house DB might pose problems if you need to switch off power in case of an emergency. I had a similar installation last week and rather went with a small essential DB in the granny flat that passed the C.O.C with no issues.

Thanks Gerrie

What if you use a changeover switch in the flat which gets fed from the main house db on its own circuit breaker? How far is the db's apart and how good is the earth between the them? For safety and peace of mind, if you run a cable it would be better to run a extra earth wire of preferably double the gauge of the current carrying wires. You should also look at the voltage drop over the distance. Is there a earth leakage in the cottage because that will influence where you tap the supply from?