I've noticed that, every now and then (randomly), my 8kW Sunsynk is pulling a whack load from the grid, even though there is plenty of sunshine...

 

Any idea why this might happen?

 

send a screenshot of your system mode screen

System mode below... I must note that it happens randomly, and only for a short period, before reverting to "normal"

 

You have 'limit to load'ticked which means you are not supplementing non essentials (with the help of CT coil) with solar. Do you have your entire house on the essential side of inverter ?

Also with your SOCs set to 70, 80 and 90 % during the day you are forcing the PV to charge the batteries before supplying power to the house items. Set those to 20 or 30 % during the day. Also depends how much power your PVs are rated for - 10kW of PV for your 8kW Sunsynk would be ideal.

48 minutes ago, Nexuss said:

You have 'limit to load'ticked which means you are not supplementing non essentials (with the help of CT coil) with solar. Do you have your entire house on the essential side of inverter ?

Whole house is on the essential circuit, but I'll uncheck

3 minutes ago, Pumba said:

Also with your SOCs set to 70, 80 and 90 % during the day you are forcing the PV to charge the batteries before supplying power to the house items. Set those to 20 or 30 % during the day. Also depends how much power your PVs are rated for - 10kW of PV for your 8kW Sunsynk would be ideal.

Have 18 x 420W Canadian Solar... but split 9 and 9 on East roof and West roof.

Looking again at your energy purchased it appears very low so I do not see a problem; that 1.89 kwhr is what happened at that particular point in time so is not continuous. One would get a better picture of what is going on by looking at the graphs if you are using Solarman Smart from a computer screen

East west is the best configuration in my opinion, but then one needs to over rate the PV capacity. eg 18 x 540 watts. I have a 5kW Sunsynk with 8 x 530 east and 7 x435 west and it pumps out the power from 6am to 6pm. Roof area availability being the biggest constraint.

17 minutes ago, bobmabena said:

Whole house is on the essential circuit, but I'll uncheck

Leave it ticked if your hole house is on the inverter , then the problem is too high SOC during the daytime . As @Pumba said.

Edited November 9, 20214 yr by Nexuss

Based on my settings above... Any ideas why I'm pulling so much from the grid?

What size solar array do you have ? Either there is not more than 1,25kw solar available or you have the SOC set to 100? That would be my guess. Maybe some clouds rolled through ? Shading issues?

Edited November 11, 20214 yr by Nexuss

5 minutes ago, Nexuss said:

What size solar array do you have ? Either there is not more than 1,25kw solar available or you have the SOC set to 100? That would be my guess. Maybe some clouds rolled through ? Shading issues?

8kW roughly, no clouds, no shade, and the inverter settings are those in post 3, but have set the % lower as recommended.

But will double check the SOC settings when home

Yea that is pretty strange. You would think there is atleast 3kw of power in the middle of the day regardless of SOC setting.

Disable Priority Load.

With Priority load enabled all of your solar generation will go towards the batteries until they reach full charge

23 minutes ago, Bloubul7 said:

Disable Priority Load.

With Priority load enabled all of your solar generation will go towards the batteries until they reach full charge

Your statement is exactly opposite to what the manual says...

How sure are you that there are no loads on the non essential side of the inverter ?  That could be the other cause of the grid usage as you are 'limiting  to load' ie not giving power to non essentials.

Entire house is on the inverter.

 

1 hour ago, bobmabena said:

Entire house is on the inverter.

 

Cool.

Go to https://home.solarmanpv.com/plant/infos/device and login. Scroll to the bottom (Historical data) where there is a graph.

Using the "Parameter" button, select (tick) the following boxes:

• DC Power PV1
• DC Power PV2 (if you are using the second MPPT)
• AC Power R/U/A
• Grid Frequency
• Total Grid Power
• Total Consumption power
• Battery Power
• SoC

The above are usually the interesting ones that will tell you what happened, and it is usually good to correlate it with weather info.

Otherwise post the graph here and we can take a look at it, but it is a bit easier for you to do it because you have the interactive pointer on your screen and you can hover over a specific time and see the exact values.

Edited November 11, 20214 yr by YellowTapemeasure

Adding some more screenshots:

 

Full sunshine during both "events"... nothing coming from the battery, only ever from he grid, even with a 100% battery.... 🙄

5 minutes ago, bobmabena said:

Adding some more screenshots:

 

 

Full sunshine during both "events"... nothing coming from the battery, only ever from he grid, even with a 100% battery.... 🙄

You said, you have  18 x 420W Canadian Solar panels. Then why are you producing only 375W during full sunshine?

Just now, PowerUser said:

You said, you have  18 x 420W Canadian Solar panels. Then why are you producing only 375W during full sunshine?

edzachery... some proper weirdness here

10 minutes ago, bobmabena said:

edzachery... some proper weirdness here

This points to problems with the PV strings. I think, you should speak to your installer.

1 hour ago, bobmabena said:

Adding some more screenshots:

 

Full sunshine during both "events"... nothing coming from the battery, only ever from he grid, even with a 100% battery.... 🙄

 

 

Using the "Select Parameter" button, select (tick) the following boxes:

• DC Power PV1
• DC Power PV2 (if you are using the second MPPT)
• AC Power R/U/A
• Grid Frequency
• Total Grid Power
• Total Consumption power
• Battery Power
• SoC

Then post your graph.

Did try previously, but the site kept complaining... Will try again