Fronius is a very popular brand when it comes to inverters, however, they also manufacture one of the industry’s best energy meter. The Fronius Energy metre works alongside the Fronius Inverter in a PV Solar System.
Why Do I Need Fronius Smart Meter?
Fronius offers the Smart Meter to transmit technical information regarding the connection to the grid and the Fronius inverter. In simple terms, the smart metre itemises how much energy is being produced by your solar system and that is being passed via the inverter, to the grid. It also itemises the power being consumed by the household and if there are any errors or notifications that need attention.
This product is a bidirectional meter that measures self-consumption (including the household load curve) and also the production from the PV system within an accuracy of 2%. This means you can see what areas of the house are consuming energy and make smart changes to limit consumption or utilise it when the solar is producing energy at peak times of the day.
The smart metre device is connected to the built-in data logger on the solar inverter and it feeds the consumption information to the handy Solar app & monitoring system from Fronius. The handy mobile app allows you to see this information in basic graphs and easy-to-understand formats – so you can remain informed.
Among other things, the Solar Web portal allows you to check daily energy balances with load curves and instantaneous power balances within the PV system. You can also take a look at your feed-in tariff & energy retailer earnings in AUD and check on the avoided CO2 emissions based on your production.
Also, if you have chosen an energy storage solution for your installation with the Fronius Symo Hybrid inverter, you can also visualise the energy stored in the battery and how this stored energy was used later on.
All of these features allow you to monitor your consumption times and integrate energy management to change your patterns of consumption if needed, to achieve bigger savings and utilise your system in the best way.
The energy meter measures voltage, frequency, current, reactive and apparent power, energy and running hours within a 2% accuracy. As an energy meter, it lets you control the amount of energy that is sold back to the grid and establishes the energy limits if necessary.
The communication is done via the Modbus RTU interface (Modbus communication protocol that conforms to the SunSpec Alliance standard) specifically developed to be synchronised with Fronius inverters.
There are two main options for the Smart Meter: the 50 kA-3 version and the 63A version which is also divided into two possibilities (the split-phase and the three-phase).
The 50 kA-3 is a three-phase energy meter that can be connected to a grid of nominal 400V.
The model tolerates a maximum surge current of 50 kA per phase and consumes less than 3 W. As you can imagine this meter is generally used for commercial applications.
The meter can be used with external transducers (current transformers for measurement) which is why it’s ideal for electrical installations where grid connections cannot be modified.
Despite the fact that the 50kA model is designed mainly for three-phase installations, it can also be used for single or dual phase installations.
It is important to note that this Smart Meter model cannot be synchronised with the Fronius Data Manager Version 1; it can only be synchronised with the Fronius Data Manager Version 2.
As a general overview, the following diagram illustrates the PV system integrated with the Fronius Smart Meter and the connection to the grid.
The installation procedure is very simple for a qualified solar electrician :
- Mount the Smart Meter on the rail within your switchboard
- Turn on the communication between the Data Manager Version 2 and the Smart Meter
- Place the current transformers on each phase of the grid to measure current values.
- Make the connections for voltage measurement along with the fuses.
- Activate the Smart Meter to transmit information to the Data Manager Interface.
- Check that you are able to see the parameters of the installation on your Solar Web account.
Even More Technical
For the electrically minded individuals who are still reading, this section is for you. Read on for a deeper dive into some of the technical electrics for installing the smart metre (a full instruction manual should be obtained directly from Fronius).
A schematic of the electrical installation for the Smart Meter can be seen in this diagram:
The RS 485 represents the terminal output with the ModBus RTU protocol that must be connected to the Fronius Data Manager via a CAT 5 Ethernet cable.
It is also mandatory to terminate the bus line with an external 120 Ω resistor in order to ensure proper bidirectional communication between the Data Manager and the Smart Meter. This resistor is included in the Smart Meter.
It is also important to note that the current transducers are not included with the Smart Meter and they need to be purchased separately when you know if the permitted secondary side of the transformer is 1A or 5A.
On the other hand, the other models are the 63 A -1 and 63 A-3 Smart Meters, one strictly for single-phase applications and the other one for three-phase applications.
Connections and grid voltages are the same as the 50 kA version, but an important difference is a current limit, which in this model is 63 A per phase, the reason why it is the Smart Meter for most residential applications.
Adding a Fronius Smart Metre to your new PV solar system can drastically improve your consumption habits and equate to more money in your back pocket – instead of the electricity providers’. It is an easy-to-use device when utilising the mobile app and it can provide you with a wealth of information that you would otherwise not be able to have access to.
To achieve the best results straight away, it’s advised to include a smart metre at the time of your solar system installation or upgrade. This way the same electrician can assist with set up and tweaking any part of the solar installation if need be. As advised previously, it must be installed by a qualified solar electrician.
The only other solar monitoring and consumption device that can provide you with similar data, but is not made uniquely for Fronius inverters – is the Solar Analytics product. Instyle Solar are trained and experienced in installing solar systems with both the Frounis smart metre and the Solar Analytics products. Read more about it here.
If you want to see how much solar or battery storage could save you over the next 5 years, then take our solar saving calculator quiz below, or talk to an Instyle Solar expert about the best solutions for home energy production, panels, inverters & storage.
Otherwise, head back to the solar blog to find even more great educational content.