What does a negative load power mean

[Robbo]

Hi, could someone help me understand these readings please. I thought Load power was the demand from the house. How can my load power & output power be negative?
Thanks

[Dave Foster]

I think we need a bit of context, normally you would not expect load to go negative - however output power goes negative when the battery is charging.

Is this a new installation?, which inverter (H1 or H3), do you have batteries, or a second solar inverter fitted ?.

[Robbo]

Hey Dave, thanks for your response.

Yes, this is a new installation fitted 5 days ago. Due to the number of solar panels there are 2 inverters, a H1 and a smaller S series. Also linked are 2 batteries

[Dave Foster]

Ok, that makes a lot more sense, if you have a second inverter (S series), when that starts to generate power in the morning because the H1 is unaware of it, the H1 sees the load go negative and sees power being exported so it will charge it's batteries and that explains the trace you are seeing.

To balance the loads and run effectively you need to fit a second CT clamp to the H1 inverter wired into CT2 in the CT/Meter connector and enable it in the H1 settings - the CT clamp should be clipped/connected to the live feed of the S series inverter.

Once that is fitted, the H1 will know to deduct the generation from the S series inverter from the load and it will show the output of the second inverter in the Foxess app.

If you need to get hold of a CT clamp, most suppliers have them - this is one here https://www.tradesparky.com/solarsparky ... aio-ranges

[Robbo]

Great, thanks very much Dave.

[AnnetteBishop]

We get an intermittent negative load. Only 1 system installed in March 2024. No generators in the house

H.51 E
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