Essential vs Non-Essential items on Inverter: Explain please

[tp3to]

So I've also been looking to get solar installed at my house but there is one question that I still don't have an answer for and two different installers couldn't clearly answer it for me.

For context I'm looking to install:

• Deye 8kw Inverter
• Alpha ESS 10kw BAttery
• 8x 540W Solar panels

Monthly usage between 300kw and 600kw.

I want to split up my home items between:

Essential:
All lights and plugs inside the house

Non-Essential:
Swimming pool pump
2x Airconditioning Units (LG Duel inverter 12000btu and 18000btu each on separate db switches)
Oven (3.5kw rated, not used often)
Washing mashine
Dish Washer

Not connected to inverter:
Geyser (want to replace with gas geyser in future)
Stove (dont want gas in house so will have to stay on eskom)

So my question....

As far as my understandin goes, when all your home items (essential and non-essential items) are switched on and uses more than 8kwh together, then the inverter will trip?

Some installers lead me to believe that no, that wouldn't happen, as the excess usage will be sourced from eskom. So if you where to use for example 10kwh on your essential and non-essential items, 4kwh would theoretically be sourced from your solar panels, 5kwh would be sourced from your battery but together it will be limited to 8kwh due to inverter limitation being 8kw and the remainder of 2kwh will be sourced from eskom?

So if that's the case, why shouldn't I connect my geyser to my non-essential items because if it where to cause me to use more than 8kwh then it shouldn't cause my inverter to trip and only the excess usage will be sourced from eskom?


My original understanding was that Solar and Battery will help supplement your non-essential items electricity usage and when eskom goes down only your essential items will be powered (limited to solar availability and battery discharge rate). But everything together shouldn't draw more than 8kwh because then it will cause the inverter to trip.

So which one is correct?

 

[Snyper564]

So I've also been looking to get solar installed at my house but there is one question that I still don't have an answer for and two different installers couldn't clearly answer it for me.

For context I'm looking to install:

• Deye 8kw Inverter
• Alpha ESS 10kw BAttery
• 8x 540W Solar panels

Monthly usage between 300kw and 600kw.

I want to split up my home items between:

Essential:
All lights and plugs inside the house

Non-Essential:
Swimming pool pump
2x Airconditioning Units (LG Duel inverter 12000btu and 18000btu each on separate db switches)
Oven (3.5kw rated, not used often)
Washing mashine
Dish Washer

Not connected to inverter:
Geyser (want to replace with gas geyser in future)
Stove (dont want gas in house so will have to stay on eskom)

So my question....

As far as my understandin goes, when all your home items (essential and non-essential items) are switched on and uses more than 8kwh together, then the inverter will trip?

Some installers lead me to believe that no, that wouldn't happen, as the excess usage will be sourced from eskom. So if you where to use for example 10kwh on your essential and non-essential items, 4kwh would theoretically be sourced from your solar panels, 5kwh would be sourced from your battery but together it will be limited to 8kwh due to inverter limitation being 8kw and the remainder of 2kwh will be sourced from eskom?

So if that's the case, why shouldn't I connect my geyser to my non-essential items because if it where to cause me to use more than 8kwh then it shouldn't cause my inverter to trip and only the excess usage will be sourced from eskom?


My original understanding was that Solar and Battery will help supplement your non-essential items electricity usage and when eskom goes down only your essential items will be powered (limited to solar availability and battery discharge rate). But everything together shouldn't draw more than 8kwh because then it will cause the inverter to trip.

So which one is correct?

If you are on the grid it will pull over 8kw from eskom - it should not "trip"

If you are LS/off grid if you pull over 8kw it will "trip"

Its not advised though to run more than 8kw it wont damage the system in the short term but its like running your car in the red.

I have "tripped"mine twice in 6 months as I forget we were loadshedding,


My whole house, oven, geyser, induction stove etc is on my essential side

You can see my system here

Snyper's Solar Farm

Hi all, I am finally getting round to making this thread. After loads of research and another bout of load shedding I finally decided to pull the trigger and load shed Eskom. Prior to going solar I already had all the lights on LEDs, house is kitted with energy efficient appliances and...

mybroadband.co.za

 

[Mzezman]

If you are on the grid it will pull over 8kw from eskom - it should not "trip"

If you are LS/off grid if you pull over 8kw it will "trip"

Its not advised though to run more than 8kw it wont damage the system in the short term but its like running your car in the red.

I have "tripped"mine twice in 6 months as I forget we were loadshedding,


My whole house, oven, geyser, induction stove etc is on my essential side

You can see my system here

Snyper's Solar Farm

Hi all, I am finally getting round to making this thread. After loads of research and another bout of load shedding I finally decided to pull the trigger and load shed Eskom. Prior to going solar I already had all the lights on LEDs, house is kitted with energy efficient appliances and...

mybroadband.co.za

What he said ^^

8kw 'limit' is when you are off grid and your essentials draw more than that. If on grid eskom will supplement. And yes you can put your geyser on non-essentials. If your CT coil is installed properly then you can pump excess PV to charge your geyser

 

[Mike Hoxbig]

I've got an 8kW inverter and hit a load of over 10kW at some point during the day. Balance is supplemented by grid.



The more likely thing that will cause tripping is the discharge rate of your battery and there is no grid available to supplement (outage, LS etc.).

If your battery is 10kWh and you can discharge at a max of 5kW/h, it will again be supplemented by Eskom. But if there is no grid available and you exceed the max discharge rate, it'll trip due to the battery being overloaded. Had this happen a couple of weeks ago.

The same holds true during the day. If your load is higher than the PV you're generating and there's no grid, it'll trip...

 

[tp3to]

Thank you for the explanation, it does clarify a few things for me.

I guess the only issue I'll have to consider when connecting my geyser to non-essential would be that if I place it on a timer to go on between 12pm and 2pm and my swimming pool pump to go on between 2:30pm and 4pm I might be using the majority of the days electricity generation and not have excess generation left to charge my battery...

edit: reason why I would like to add my geyser to non-essential is because I would like to try and save as much as I possibly can on my electricity bill. At the moment my bill is between R800 and R1300 and if I can save up to R1000 a month it should offset the amount I'm going to pay for the system.

Also, I'm not too concerned about it tripping while on battery only because all my items on essential shouldn't really go over 5kw. I have all my lights on led already and I'm a bachelor so managing my power usage during load shedding at night is easy. Only thing that might cause it to use more than 5kw would be if I put on my kettle, microwave, air fryer and render on my pc all at once which wont ever happen lol.

 

[tp3to]

@Mzezman

Can you please clarify what you mean about the CT coil?

I'm not experienced with that and would like to know what must ask my electrician to check if that is a problem or not.

 

[Mzezman]

@Mzezman

Can you please clarify what you mean about the CT coil?

I'm not experienced with that and would like to know what must ask my electrician to check if that is a problem or not.

Current Transformer coil - it comes in the box with the inverter and essentially allows / blocks feeding back to the grid. Some installers put it in the inverter - this means that you cant export any power (whether to grid or to non-essentials). If it is installed correctly (in your main DB on the incoming Eskom feed from the street) then the devices on non-essential (between the inverter and the CT coil) can be powered by the inverter using PV.

 

[Mike Hoxbig]

I guess the only issue I'll have to consider when connecting my geyser to non-essential would be that if I place it on a timer to go on between 12pm and 2pm and my swimming pool pump to go on between 2:30pm and 4pm I might be using the majority of the days electricity generation and not have excess generation left to charge my battery...

If your geyser is non-essential it will be powered by Eskom. Essentials are powered by the inverter.

You can set your inverter to either power your essentials first (with excess power going to charge the battery), or charge batteries first (with excess power going to your essentials). The inverter will use Eskom to power all essentials if there isn't enough PV generated in either case.

Then if there is excess PV generated after this condition is met, you can set the inverter to send excess power to your CT (and therefore your non-essentials) as @Mzezman explained...

 

[itareanlnotani]

Don't forget you also have an aux output which can be configured to provide power if there is excess or battery is full.

This is perfect for things like Pool pumps.

If there is insufficient battery or solar pv (configurable by yourself), then it turns that aux output off.

If there is sufficient power it gets turned on, and your pump , geyser etc can run.

 

[Koosvanwyk]

So I've also been looking to get solar installed at my house but there is one question that I still don't have an answer for and two different installers couldn't clearly answer it for me.

For context I'm looking to install:

• Deye 8kw Inverter
• Alpha ESS 10kw BAttery
• 8x 540W Solar panels

Monthly usage between 300kw and 600kw.

I want to split up my home items between:

Essential:
All lights and plugs inside the house

Non-Essential:
Swimming pool pump
2x Airconditioning Units (LG Duel inverter 12000btu and 18000btu each on separate db switches)
Oven (3.5kw rated, not used often)
Washing mashine
Dish Washer

Not connected to inverter:
Geyser (want to replace with gas geyser in future)
Stove (dont want gas in house so will have to stay on eskom)

So my question....

As far as my understandin goes, when all your home items (essential and non-essential items) are switched on and uses more than 8kwh together, then the inverter will trip?

Some installers lead me to believe that no, that wouldn't happen, as the excess usage will be sourced from eskom. So if you where to use for example 10kwh on your essential and non-essential items, 4kwh would theoretically be sourced from your solar panels, 5kwh would be sourced from your battery but together it will be limited to 8kwh due to inverter limitation being 8kw and the remainder of 2kwh will be sourced from eskom?

So if that's the case, why shouldn't I connect my geyser to my non-essential items because if it where to cause me to use more than 8kwh then it shouldn't cause my inverter to trip and only the excess usage will be sourced from eskom?


My original understanding was that Solar and Battery will help supplement your non-essential items electricity usage and when eskom goes down only your essential items will be powered (limited to solar availability and battery discharge rate). But everything together shouldn't draw more than 8kwh because then it will cause the inverter to trip.

So which one is correct?

Items on the essential circuit will be limited to the maximum AC passthrough current. This I think is 50A on the 8Kw Inverter.

So in theory, if your essential items are pulling 50A, then the inverter will supply up to a maximum of 8000W from DC source (PV + battery + xxx) if it is available, the rest, to get to the 50A, will be taken from Eskom and will merely be passed through the inverter to make up the shortfall.

If eskom is not available then you are limited to 8000W. AC Passthrough is just on the essential loads and does not apply to the non essential loads.