Displayed Load is always zero

[tromso]

On 1st November 2024, 9 solar panels were installed on my house roofs in two arrays – the first of 5 panels, the second of 4 panels. Each panel has a nominal max output of 405 watts, giving a possible total of 3.6kW.

There was no battery storage required, so the inverter fitted was a Fox ESS F3600, with a WiFi connection to the house network router.

The installers left no documentation but said that all information was available online and that I would be able to monitor the system by downloading the FoxCloud app to my Android mobile phone.

I have downloaded and installed the FoxCloud2.0 app and used it to verify that the system appears to be working, but I am puzzled by how little information it is providing compared with the amount of information it seems to be able to provide. Here are the readings it showed at 10:20 on 30th January 2025 (a fairly sunny day):
PV information:
PV Voltage - Current - Power 1.318
PV1 Voltage 163.8 Current 7.2 Power 1.179
PV2 Voltage 115.5 Current 1.2 Power 0.139
PV3 Voltage 0 Current 0 Power 0
PV4 Voltage 0 Current 0 Power 0
AC information:
Voltage 242.8 Current 5.0 Power 1.258 Frequency 50.1
Load information:
Daily load consumption 0kWh
Total load consumption 0kWh
Total load power 0kW
Grid load power -1.258kW
EPS load power -kW
Grid information:
Grid Status Export
Daily feed-in energy 0kWh
Total feed-in energy 0kWh
Daily purchased energy 0kWh
Total purchased energy 0kWh
Feed-in power 1.258kW
Purchased power 0kW

I found the installation/user manual for the inverter online and in the small print it mentions an optional CT clamp but implies that the clamp is only required for limiting any exported power to the grid to a maximum of 5 kW so would not be required for my system which has a maximum output of only 3.6 kW. The installers left a CT clamp and a communication connector for plugging into the inverter but did not fit the clamp and did not connect it to the inverter. I did not expect it to make any difference but I tried fitting the clamp and connecting it to the inverter as shown in the user manual. As I expected, it made absolutely no difference to the readings shown on the FoxCloud2.0 app so I have removed the clamp and disconnected it from the inverter.

It appears to me that neither the actual input from the grid nor the load have ever been measured. These are my questions:
Should that information be available from the inverter that has been fitted or is it only available from a more sophisticated inverter?
Is that information only available for systems with battery storage?
Is that information somehow obtained from a smart meter? At the moment, the house does not have a smart meter – one is being fitted in the near future. There is a supplementary meter (Emlite model ECA2.nz) that was fitted near the inverter when the system was installed - it only shows 3 values (total Import consumption, total Export consumption and net consumption, where total import consumption is still showing zero, thus matching the total feed-in energy shown by the app).

[Will]

My answers in bold.

Should that information be available from the inverter that has been fitted or is it only available from a more sophisticated inverter? Without a CT clamp you will only see solar generation in the app. No grid data or house load data
Is that information only available for systems with battery storage? Technically with the CT clamp installed you can get most of the data, remember string inverters turn off when the sun goes down so you lose grid and house load data when the sun isn't shinning which defeats the point really.
Is that information somehow obtained from a smart meter? At the moment, the house does not have a smart meter – one is being fitted in the near future. There is a supplementary meter (Emlite model ECA2.nz) that was fitted near the inverter when the system was installed - it only shows 3 values (total Import consumption, total Export consumption and net consumption, where total import consumption is still showing zero, thus matching the total feed-in energy shown by the app). Sadly grid smart meters are not the same as a energy monitor meter so will be unlikely to work.

[tromso]

Hi Will, and thanks for the quick response.

I agree with you that a CT clamp is obviously necessary to measure the current, even though the Inverter manual implies that a CT clamp is only required for the export management function, so I have refitted the CT clamp onto the line cable into the house from the outside meter as the user manual suggests (see below)

The placement suggests to me that the CT clamp is measuring the current to or from the grid, rather than the load current, but I suppose that the load current can be derived by subtracting the current sent to the grid from the current output from the inverter (or adding the current received from the grid to the current output from the inverter).

I also checked the connection from the CT clamp to the communication socket on the inverter to ensure that the CT+ wire is connected to pin 1 and the CT- wire is connected to pin 2 (the manual says that the CT+ wire is white and the CT- wire is black, but the wires from the CT clamp supplied are red and black, so I assumed that the red wire was the CT+).

However, connecting the CT clamp again made no difference to the zero values shown on the FoxCloud2.0 app, so I am wondering if the CT clamp is disabled by the inverter and I need to configure the inverter's configuration setting.

[Will]

Oh yes, you will need to enable it on the inverter.

[tromso]

Thanks again Will.

I checked the inverter configuration (luckily, the default password was still valid) and, sure enough, the CT clamp function was shown as disabled, so I enabled it.

Just as I had finished doing so, the light level outside reduced enough for the inverter to go offline, so I will check tomorrow to see what difference the configuration change has made.

[tromso]

All good now! Thanks for the advice.