Network type
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Single-phase (230 V). Single-phase power is well known from classic 230 V household sockets. However, this also often includes models for other alternating voltage values - for example, 110 V.
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Three-phase (400 V). Three-phase power supply with a voltage of 400 V is used mainly for energy-hungry devices for which 230 V networks do not provide enough power. This option can be used both for private households and in the industrial sector.
— Single-phase / three-phase. Models with the ability to connect to both single-phase power supply at 230 V and three-phase power supply at 400 V. This allows them to be used with both household and industrial networks - depending on which option is more convenient at the moment.
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DC (constant voltage). This category usually includes a few inverters for campers (motorhomes) (see “Device Type”). They are designed for operation in automotive networks with a constant voltage of 12/24 V.
Euro efficiency
The European inverter efficiency is measured based on several load values (e.g. 10%, 30%, 50%, 100%), which better reflects the actual operating conditions of the device. Indeed, in fact, inverters rarely operate at full power in constant mode. To calculate the Euro index, the weighted average of the inverter efficiency at different load levels is taken into account. Note that there is no single generally accepted formula here - it may vary depending on the specific standard or equipment manufacturer. Nevertheless, Euro efficiency allows you to more accurately assess the efficiency of the inverter under conditions of partial and full power use
Rated AC current
The current strength that the device is capable of stably and safely delivering when operating in rated mode (i.e. for the longest possible time without the risk of overloads and failures). The indicator is expressed in Amperes (A).
Maximum AC power
The maximum current in amperes (A) that the inverter, when operating, is capable of outputting without overloads or failures.
Maximum charge current
The maximum amount of direct current in amperes that the inverter can convert. If the solar panel produces a current exceeding this value, the inverter simply does not use it. This is often justified when connecting an inverter to high-power solar panels - the maximum input current of the inverter is reduced to acceptable values so that moderate-sized wires can be used to transmit energy.
Max. power
The maximum allowable input power from solar panels, expressed in kilowatts (kW). Let us remember that 1 kW contains 1000 W.
When selecting an inverter based on this indicator, they are based on the total power of the solar panels involved in generating electricity. Moreover, it often makes sense to select models with an inverter input power slightly less than the maximum power of solar panels - for example, if they are shaded part of the time or for other reasons do not receive enough sunlight during the day. The power of the solar battery should not exceed the power of the inverter by more than 30%. However, for some inverters the excess can be only 10%, while for others it can be up to 100%. It is better to clarify this point in advance.
Operating voltage PV
The operating range of the inverter is usually located between the starting voltage and the maximum voltage. This interval is indicated in volts.
Short circuit current
The maximum solar panel short circuit current that the inverter can accept without the risk of breakdown or emergency shutdown. The parameter is usually indicated in amperes.
Controller
Built-in Maximum Power Point Tracking (MPPT) system for monitoring the maximum power points of photovoltaic modules in solar panels. It determines the most optimal ratio of voltage and current drawn from the solar panels, thereby ensuring maximum performance of individual strings (chains of series-connected panels). An
MPPT controller is useful under any external weather changes, allowing solar panels to generate power even in cloudy conditions. Modern inverter models can contain either one or
several MPPT trackers (up to six), which allow for the connection of multiple arrays with different orientations and angles of inclination, thereby eliminating the mutual influence of one array on another. Each MPPT controller output is designed to connect one string.
