PV surplus charging: Additional energy meter

PV surplus charging: Additional energy meter

The AC SMART has two options for using the PV surplus charging function. In the following, you will learn in detail which basic requirements must be fulfilled for this. You will then find step-by-step instructions on how to install an additional energy meter. If you want to implement PV surplus charging with connection to an inverter, you will receive step-by-step instructions on this page.

Please note that the steps described here may only be carried out by trained electricians.

Basic requirements

To use the PV surplus charging function, you can use all variants of our AC SMART VALUE and ADVACNED. These require firmware version 01.02.15 or newer. You can see which firmware version is installed on your AC SMART in the web server of your AC SMART.

If the installed firmware version of your AC SMART is out of date, you will find the latest firmware version in our Weidmüller online catalogue for the existing AC SMART under the item Downloads.

Modbus RTU energy counter

For PV surplus charging by means of an additional energy meter, you need a Modbus RTU energy meter. In our product portfolio you will find the following energy meters that you can use for this application:


Power measurement/indication for 1-, 3-phase network, CT use, pulse output, Modbus RTU


Power measurement/display for 1-, 3-phase mains, 100 A, direct measurement, pulse input, Modbus RTU

Important: Please use the connected load as a guide when selecting the energy meter.

For a connected load > 100 A, suitable current transformers must also be selected. You can also find these in the Weidmüller online catalogue here.

PV surplus charging by means of an additional energy meter

After your AC SMART has been installed according to the installation instructions (Weidmüller online catalogue under Downloads), you can start with the connection of the additional energy meter and the settings in the web server of your AC SMART. The necessary steps are described in the following points.

1. Please connect the selected energy meter according to the wiring diagrams listed for single-phase or three-phase operation:



2. Open the web server of your AC SMART, log in as Admin and configure your AC SMART according to the operating instructions (see chapter 9 of the operating instructions).

In the menu item Load management settings under General your AC SMART must be selected as Control box for PV surplus charging. In addition, the item Connection to external measurement must be set to RTU and then confirmed with Save.

3. In the menu item Load management settingsunter PV-Charging you can now activate PV surplus charging. Please activate the corresponding switch and confirm this with Save. In addition, you can define settings of the PV surplus load such as the PV mode in this menu item.

Important: If several wallboxes are controlled via the integrated load/charge management of the AC SMART, PV charging must only be activated for the control box. This controls the satellite boxes according to the settings for PV surplus charging and for load/charge management. For the Satellite boxes please only make the other settings under this menu item .

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