On 2022/02/05 at 11:23 AM, Leshen said:

You still not answering the question. I'm asking you why a 32A breaker on the grid side and not 63A?

It seems there are some areas where a grid tied is still not understood not withstanding the long topic about a grid tied tripping or not.

A Sunsynk 8kw can only generate 35A as a maximum to feed to the grid(230V AC). It cannot feed 63A. This also happens to be the maximum feed through if one runs on bypass. For safety one can lower this MCB to the actual maximum current of the 5kw unit when running as a grid tied only.

From other comments it seems like they don't want these units to be loaded to 100% of their actual output.

It I had to select a MBC for the input/output on a Synsynk I will also use a 32A MCB. 

For sure not an isolator or 63A.

On 2022/02/12 at 12:01 PM, Scorp007 said:

It seems there are some areas where a grid tied is still not understood not withstanding the long topic about a grid tied tripping or not.

A Sunsynk 8kw can only generate 35A as a maximum to feed to the grid(230V AC). It cannot feed 63A. This also happens to be the maximum feed through if one runs on bypass. For safety one can lower this MCB to the actual maximum current of the 5kw unit when running as a grid tied only.

From other comments it seems like they don't want these units to be loaded to 100% of their actual output.

It I had to select a MBC for the input/output on a Synsynk I will also use a 32A MCB. 

For sure not an isolator or 63A.

The SunSynk 8.8 kW machine can pass through up to 12 kW (MAX) when connected to mains. This is +- 50A, so a 32A MCB is a bit small if you intend having all load on the UPS side like I do. I have had over 10 kW pass through my machines to essential loads.👍

I do not use my machine as only a grid tied inverter to push back though, as all my loads are essential.

Oops you're discussing the 5 kW machine.😂

Edited March 11, 20224 yr by TimCam

@TimCam, for how long did you have the 10kW plus load running thru your essentials circuit.

+- 15 minutes that I noticed it, Geyser on with stove plates and oven, plus rest of house. 👍 SunSynk 8.8 kW, not the 5.5 kW machine though.

2 hours ago, TimCam said:

+- 15 minutes that I noticed it, Geyser on with stove plates and oven, plus rest of house. 👍 SunSynk 8.8 kW, not the 5.5 kW machine though.

The 8kw unit is a beast. 

In an earlier post we got some sizes mixed - you and me. The 5kW unit has a pass through of 35A full time as per spec. To limit it just below max this was how I got to my answer to use a 32A MCB instead of a isolator.

In grid tied mode the 5kW can output 21.7A to the grid as per the spec (old) I saw when assisting someone who decided on the 5kW model some time ago.

And here we have our 2nd LS for the day.

What's the smallest battery you can use with this 5k inverter?

3 hours ago, AlexanderR said:

What's the smallest battery you can use with this 5k inverter?

There are practical guidelines. If you are not going to use say 1kw at any time the battery can be small but normally one end using the power available.

Installing such a unit you want to cycle the battery and use it unless as few people do they use it for grid tied for maximum gain.

Edited March 12, 20224 yr by Scorp007

So, if the grid goes down and solar is available, will the 5kw Sunsynk switch off? 
 

Meaning, if I have loadshedding during the day, will I have no power?

On a pure grid tied(no battery), correct, if there is no grid, the inverter will shut down 

Any way to get around this? 

Will a 20AH battery keep the inverter up when there is no grid and there is sufficient solar?

55 minutes ago, McGuywer said:

Any way to get around this? 

Will a 20AH battery keep the inverter up when there is no grid and there is sufficient solar?

Yh a small battery will do

@McGuywer Unfortunately solar power is not a 100% consistent supply, even on a clear day the amount of power being produced fluctuates, sometimes quite dramatically.

When the inverter has no battery it is only able to run on grid-tied mode which means that is syncs with the grid's frequency and feeds in as much power as it can produce and then pulls any extra power it needs from the grid. If there is no grid to sync to, the inverter is unable to produce power. 

To produce power without a grid to sync to the grid needs to switch to inverter mode where the inverter will generate it's own grid frequency.  It however needs a battery to fill in the gaps when the solar power alone is not enough.  

One of the main things to be aware of when looking at batteries is the "C Rating" of the battery.

That is the amount of power the battery can feed out in relation to it's capacity. 

For example, if you have a 2kw 48v battery with a 0.5c, it will be able to supply 1kw of power or approx. 20.8A @ 48v

In the example, the inverter will run off the battery with no problems, as long as you do not pull more than 1kw of power out of it. If the inverter tries to do this, the batteries BMS will protect the battery and cut the power which will result in the inverter coming up with and error and tripping out. 

I think that having the inverter tripping will happen a lot more than you anticipate and would suggest that whatever battery you look at you ensure that it is able to supply enough power to the inverter to run it at full power, so a 5kw 1c battery for a 5kw inverter would be my suggestion.  

 

Thank you for the replies.

 

Seems to me, I need to save a bit more to install solar.

The idea (since two years ago) has been to get a 5kw Sunsynk and a couple of panels up. The idea was to reduce my electricity bill and have power with loadshedding during the day. Seems that I would need batteries from the start, so this puts this dream on hold.

 

On average, I use 2Kwh per hour. That is 48 units per day.

I have now reduced the temperature on my two geysers to 55 degrees and the pool pump is only running 6 hours a day.

We do not use the stove a lot, we have a 1500w air fryer.

Our tenant is moving out at the end of April, so that will also help.

I know I will need to lower my daily usage but I do not see where else. I figured gas stove & gas geyser for the flat.

Not sure if a gas geyser works for a bath? If yes, perhaps I must install one for the main house as well.