switching device
Energy manager for feeding excess solar power into the socket. Reduce your hot water and electricity costs by feeding excess photovoltaic energy from the fothermo boilers and heating elements directly into your power grid via a micro PV inverter.
![](http://fothermo.com/cdn/shop/files/fothermo_Umschaltgeraet_Vorbestellung_600x600.jpg?v=1721837738)
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Save around €125 on electricity costs per year
Feed around 400 kWh of excess photovoltaic energy from the boiler or heating elements into the power grid via a micro PV inverter.
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2,000W balcony power plant
Use the power of up to 2,000 Wp photovoltaic power. Because a maximum of 800 W is fed in via the inverter, the entire system is still a balcony power plant.
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Feed in 600 W / 800 W via a micro PV inverter.
Excess energy is fed into your own power grid via a micro PV inverter.
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Intelligent control
No energy is lost. As soon as the boiler is fully heated or more photovoltaic power is available than the boiler can use, excess energy is fed into the power grid.
Product features
Reduce hot water and electricity costs
Maximum use of energy through efficient hot water generation and intelligent electrical surplus feed into the power grid.
Feed up to 600 W / 800 W into the power grid via a micro PV inverter.
Excess electricity from the boiler is simply fed into the power grid via a micro PV inverter.
2,000 W balcony power plant
Use the power of up to 4x photovoltaic modules or 2,000 Wp photovoltaic output. Because a maximum of 800 W is fed in via the inverter, the entire system is still a balcony power plant.
Intelligent control
No energy is lost. As soon as the boiler is fully heated or there is more photovoltaic power available than the boiler can use, excess energy is fed into the power grid.
display
The display of the switching device always shows the status of all connected electrical consumers.
![](http://fothermo.com/cdn/shop/files/fothermo_Umschaltgeraet_draufsicht_01_700x700.jpg?v=1706721094)
Product description
The fothermo switching device is the solution for using excess electricity from the boiler in your own home network. Especially in the summer months, it often happens that the photovoltaic boiler is already completely heated up in the morning hours.
If the photovoltaic output is already high in the morning, the switching device assumes that the boiler will be fully heated up during the day. Therefore, the switching device switches individual PV modules to the connected micro PV inverter in the morning, so that electricity is fed into the house network throughout the day. This largely covers the basic load of the house.
As soon as the boiler has completely heated up, all connected photovoltaic modules are switched to the micro PV inverter.
The switching device always prioritizes the photovoltaic boiler before surpluses are fed into the house network, thus ensuring maximum efficiency of the entire photovoltaic system.
![](http://fothermo.com/cdn/shop/files/fothermo_Umschaltgeraet_seite_01_40e998b7-236b-4328-9135-0ad28f72b6a0_700x700.jpg?v=1721837744)
easy installation
The switching device is mounted on the wall using four screws.
Photovoltaic modules or electrical consumers are connected via simple screw terminals on the switching device.
The switching device has four photovoltaic module inputs, which can be recognized by the green colored terminal blocks. The photovoltaic modules or the extension cables of the photovoltaic modules are connected directly to the switching device. A simple screwdriver is required for this.
Up to three electrical consumers are connected to the blue terminal blocks. The fothermo switching device is designed for use in combination with the following devices: 1x fothermo photovoltaic boiler or heating element; 2x inputs of a micro PV inverter
![](http://fothermo.com/cdn/shop/files/fothermo_Umschaltgeraet_Anschlussschema_700x700.jpg?v=1710430180)
![](http://fothermo.com/cdn/shop/files/Schematic_2048x653.png?v=1721837744)
Information to download
Technical specifications
![](http://fothermo.com/cdn/shop/files/fothermo_Umschaltgeraet_draufsicht_01_aa923539-ffb9-43e3-9c6b-f647cb294f2f_960x960.jpg?v=1721837744)
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Specification
1 - 4 photovoltaic modules can be connected to the switching device. The orientation of the photovoltaic modules does not matter. The maximum power per photovoltaic module is 500 W.
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Specification
Up to 3 consumers in total.
1x fothermo boiler (hybrid or offgrid) or heating element
2x micro PV inverter input (2x - 300 W / 400 W) -
Specification
7" x 3" x 1.6"
Connection plan - boiler
The energy is primarily fed into the photovoltaic boiler via the fothermo switching device.
The switching device detects when the boiler has finished heating or when more photovoltaic power is available than the boiler can convert into heat. In these cases, excess energy is fed into the house network.
On particularly sunny days, the switching device starts feeding in partial surplus power from 1 - 2 modules early in the morning. This ensures that the house's basic electrical load is covered in the morning hours.
This means you save not only on hot water costs but also on electricity costs.
![](http://fothermo.com/cdn/shop/files/fothermo_Schaltplan_80_Hybridboiler_USG_1020x574.jpg?v=1713886449)
Connection plan - heating element
In this system, too, the photovoltaic energy is primarily consumed in the heating element.
As soon as more solar power is available than the heating element can convert into heat, excess energy is fed into the home's own network.
![](http://fothermo.com/cdn/shop/files/fothermo_Schaltplan_Heizstab_USG_1020x574.jpg?v=1713888536)
Connection plan - storage tank
In this example, excess photovoltaic power is fed into the house grid via a 600 W / 800 W micro PV inverter. The fothermo switching device is required as an energy manager for this.
The switching device detects when the storage tank is fully heated or when more photovoltaic power is available than the storage tank can convert into heat. In these cases, excess energy is fed into the house network.
This means you save on electricity costs as well as hot water costs. This is a huge advantage over solar thermal energy. No energy is lost.
![](http://fothermo.com/cdn/shop/files/fothermo_Schaltplan_Standspeicher_USG_1020x574.jpg?v=1713886260)
Explanatory video: The simplest option for a 2,000 W balcony power plant to reduce hot water and electricity costs. The fothermo switching device!
600 W / 800 W - compatible micro PV inverters
The switching device was developed to be compatible with as many micro PV inverters as possible. You can use both 300W and 400W as well as 600W and 800W micro PV inverters. Before connecting the inverter, make sure that it has a voltage range of less than 60V . These are all inverters to which 1 or 2 photovoltaic modules can be individually connected to the inverter. Below is a list of compatible inverter brands:
- AE conversion
- Hoymiles
- Envertech
- Deye
- ...
With incompatible inverters, the input voltage of the photovoltaic modules is significantly higher than 65 V. This is because the photovoltaic modules are connected in series to an inverter input. Typically the voltage range is 100 V to around 400 V. GROWATT brand inverters, for example, are not compatible with the fothermo switching device.
![](http://fothermo.com/cdn/shop/files/fothermo_Micro_PV_Inverter_984x700.jpg?v=1687984765)
possible applications
2,000 W balcony power plant to reduce hot water and electricity costs for heating systems with fothermo heating rod.
Reduce your hot water and electricity costs with the fothermo #OilAway set. As soon as the heating element's buffer storage is completely heated up, excess energy is fed into your own power grid via a micro PV inverter. The switching device ensures maximum efficiency of the entire photovoltaic system. Especially in the summer months, the hot water tank is already fully heated up by midday. With the switching device, all excess energy can now be used.
![](http://fothermo.com/cdn/shop/files/fothermo_Heizstab_Wechselrichter_Set_726x700.png?v=1695329576)