UPDATED 19/01/2026 to include new video guides.
All single-phase hybrid inverters and AC chargers are supplied with a CT clamp & cable – this is essential for grid import/export monitoring and it a compulsory element of any installation with batteries. You could install a hybrid inverter without batteries and choose not to install the CT (for example if you were installing a PV system with a view to adding batteries later); however, we would strongly recommend that the CT is installed regardless, as this will provide the customer with visibility of import, export and load demand; and this is useful even in the absence of battery storage.
Please note, if you do install a hybrid inverter without batteries and choose to not install the CT, you must disable the CT option in the inverter settings, failure to do this will put the inverter into an error state.
The cable provided is approximately 10m in length; however, this can be extended up to a maximum of 30m. Beyond this distance you would need to substitute the CT for a single-phase modbus meter. There is a separate Tech Hub article covering the installation of that device. You can also shorten the CT cable if required.
The cable provided is 2 core RS485 cable, and you can extend like for like, or use CAT5 twisted pairs.
The CT must be clamped around the incoming live tails and the embossed arrow must point in the direction of the grid (away from the load).
The CT is also an option for grid-tied (non-storage) inverters such as the S, F and G series models in order to provide the customer with visibility of import and export. However, the CT is not supplied as standard with these models and would need to be purchased separately (we recommend purchasing a Fox issued CT to ensure it is compatible and the ratio is correct).
Single-Phase Hybrid Inverters & AC Chargers (H1, AC1, H1-G2, AC1-G2, KH Series, KA Series, PowerQ)
Meter plug connections for the hybrid/AC Charger inverters are pins 7/8.
Please note, there are 2 types of meter plugs for the single phase inverters (an 8 pin connector and a 16 pin connector), however the pin configuration is the same.
CT Connections for the grid:
Negative – 7 and Positive – 8
Single-Phase Gried-Tied Inverters
Meter plug connections for the F and G series inverters are pins 1/2.
CT Connections for the grid:
Negative – 2 Positive – 1
S series inverter connections are:
Negative – 9 Positive – 10
Monitoring Secondary PV
If there is a secondary inverter/generation source on site (PV separate to either AC charger or Hybrid inverter, for example a separate or existing PV array installed with another inverter brand) we recommend that you install a secondary CT clamp to pins 5 and 6 of the AC charger/Hybrid inverter.
Please note, the secondary CT should be clamped on the AC output of the secondary inverter/generation source with the embossed arrow pointing in the direction of the Grid (back to the Usage/Load source). If connecting a secondary CT for this purpose please ensure you enable CT2 in the settings of the hybrid inverter or AC charger. This would be an additional purchase and we recommend you source a Fox issued CT clamp.
Full video guide here:
Negative – 6 positive – 5
Things to note:
- When using the 16 pin plug for CT clamp connections you MUST use the ferrule crimps provided in the box.
You can test the functionality of the CT clamp by removing the CT clamp from the main incoming tails and testing the positive and negative conductors of the CT clamps (results should be between 240-250 ohms).
