Here's my setup:

• Inverter model: 8K-SG05LP1-AU
• Grid L/N/PE => GRID port
• House load L/N => LOAD port
• 2 strings of solar panels => PV ports
• Battery setting: No batt
• System work mode: Zero export to load (sell solar disabled); Load first

Currently, the "DC" and "AC" leds are turned on, but "Normal" led is off. At the main screen, inverter status is "OFF". 

Currently, load is drawing from grid only, and solar power is not used. However, at the PV page, it can be seen that ~300V is detected at each PV input.

Is there any setting that I can configure to add solar power to the load?

Someone suggested that I can only use solar power if a battery is installed. But my understanding is as long as grid is present, solar should be able to work regardless of whether a battery is present.

3 hours ago, dobber said:

Zero export to load

That sounds to me like you don't want the load to use solar...

I believe "Zero export to load" means it will provide enough power to LOAD, but will not sell power to the grid?

This means it will use solar first to try to power LOAD, and supplement the rest with GRID.

Is my understanding incorrect?

Thx.

37 minutes ago, dobber said:

I believe "Zero export to load" means it will provide enough power to LOAD, but will not sell power to the grid?

This means it will use solar first to try to power LOAD, and supplement the rest with GRID.

Is my understanding incorrect?

Thx.

Yes, that is correct.

MdF

It is quite simple: The load port is actually the UPS port - it needs a battery to be functional.  You need all your loads to be connected to the grid port, which is both an input and an output port.

From Sunsynk training manual:

IMPORTANT:
When using our inverter without batteries, you can only connect to the grid connection, which is both an
input and output, similar to a standard string inverter. Many users misunderstand this point and mistakenly
connect the outputs to the ‘LOAD’ and the input to the ‘GRID’ connection when there are no batteries. This is
simply wrong, and the inverter will not function correctly.
In Figure 4 and Figure 5, you can see a ‘GRID’ input and a ‘LOAD’ input. Do not think that the ‘GRID’ is
the input and the ‘LOAD’ connection is the output. The ‘GRID’ is an input and an output, and the ‘LOAD’ is a
UPS.
Therefore, when you have batteries, you will connect only essential loads such as lights, security devices,
routers, and computers to the ‘LOAD’ connection and, with the ‘GRID’ connection, you will connect the nonessential
loads such as most sockets, air conditioning, heaters, etc. However, if you do not have batteries,
you will not use the ‘LOAD’ connection. You must connect all your loads to the GRID input.

 

Edited November 10, 20241 yr by Calvin

Thanks Calvin. I think you explanation makes a lot of sense.

I have a battery coming end of the month.

We will see how it goes then.

I have a follow-in question. In my current config, if I change work mode to "Selling first", wouldn't the inverter turn on and start selling solar power back to the grid?

But when I did this, inverter stays off, and no power was produced.

Any idea why? Thanks!

2 hours ago, dobber said:

I have a follow-in question. In my current config, if I change work mode to "Selling first", wouldn't the inverter turn on and start selling solar power back to the grid?

But when I did this, inverter stays off, and no power was produced.

Any idea why? Thanks!

Is the inverter powered on? Do you have a blue light ring around the On/Off button at the bottom of the unit?

1 hour ago, JayMardern said:

Is the inverter powered on? Do you have a blue light ring around the On/Off button at the bottom of the unit?

Most definitely!

You sure its on?

The "Normal" light should be illuminated and the display should say "ON"

Yes, positive. Blue ring around ON/OFF LED button was on. When I pressed it again, blue light goes off. Pressed it again, blue light goes on. But inverter status on main screen remains "OFF".

That's exactly the problem I am trying to diagnose:

1) Correct voltages at PV

2) Normal light is off

3) Inverter status is off

Shouldn't inverter still work if:

1) No battery

2) Work mode is "Sell first"

3) Load port is connected

Unless you are telling me if inverter can only turn on if battery is connected. However, from my research, it seems inverter should still be able to work even if no battery connected.

On 2024/11/11 at 1:41 AM, Calvin said:

It is quite simple: The load port is actually the UPS port - it needs a battery to be functional.  You need all your loads to be connected to the grid port, which is both an input and an output port.

From Sunsynk training manual:

IMPORTANT:
When using our inverter without batteries, you can only connect to the grid connection, which is both an
input and output, similar to a standard string inverter. Many users misunderstand this point and mistakenly
connect the outputs to the ‘LOAD’ and the input to the ‘GRID’ connection when there are no batteries. This is
simply wrong, and the inverter will not function correctly.
In Figure 4 and Figure 5, you can see a ‘GRID’ input and a ‘LOAD’ input. Do not think that the ‘GRID’ is
the input and the ‘LOAD’ connection is the output. The ‘GRID’ is an input and an output, and the ‘LOAD’ is a
UPS.
Therefore, when you have batteries, you will connect only essential loads such as lights, security devices,
routers, and computers to the ‘LOAD’ connection and, with the ‘GRID’ connection, you will connect the nonessential
loads such as most sockets, air conditioning, heaters, etc. However, if you do not have batteries,
you will not use the ‘LOAD’ connection. You must connect all your loads to the GRID input.

 

What does “UPS port” mean exactly? That it uses only battery power and not PV directly? What are the implications for whole house backup where the main panel is connected to Load and only the grid is connected to Grid? I think that in that scenario Zero Export to Load and Zero Export to CT are effectively the same. If there’s a practical difference I’d like to know what it is. I don’t have a battery yet so I can’t experiment. 

UPS port is the same as load port or essential loads.  Power is sourced from PV, grid and/or battery.

If you do not have a battery then with these inverters you need your loads to be connected to the grid/non-essential port, not the load (UPS/essential loads) port.

My setup is like you describe (all loads on load port, only grid on grid port, with batteries) and everything works exactly as one would expect/hope.  The only thing I cannot comment on is the export function - I do not sell back to the grid.

Does it work like this on all of the modes? No battery = no power on the Load terminals? The Deye manual sure doesn’t make this clear, saying that for “Zero Export to CT” power is supplied to both the backup load and home load, with no caveats about requiring a battery.

8 minutes ago, Haysdb said:

Does it work like this on all of the modes? No battery = no power on the Load terminals? The Deye manual sure doesn’t make this clear, saying that for “Zero Export to CT” power is supplied to both the backup load and home load, with no caveats about requiring a battery.

Although if you say "backup load" it somewhat implies there's a backup battery for that port. Just not exactly explicit, I'll give you that.

That’s a valid point.

I’d still like to know for sure that the Load terminals are only ever powered if there is a battery. I think this seems likely, but I keep getting bitten in the ass by my assumptions.

ChatGPT gave a sensible sounding hypothesis for requiring battery for the Load terminal: “The load terminals may be left unpowered to avoid providing unreliable or unregulated power to critical loads.”

Hi, did this problem ever get fixed,? just installed a Deye 5KW inverter today and have the same issue.

Yes, I was able to fix it by disabling DRM (Demand Response Mode) under advanced setting, then wait for 2 minutes for the inverter to adjust to the new setting.

Wow, thanks so much, I thought I was going mad, it's working perfectly now. Thank you .

Glad to be of help. I know what you mean by going mad... my experience as well, after almost a week of not getting it to work!

But now it's been working solid for a few months now, and got it integrated with Home Assistant so that I can collect stats and perform analysis. Loving it!!

Worked for me too! Thank you.