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Identification: MD-AL-GI-00
Rev. 1.1 of 15/03/2021 - Application: GID
User’s Manual 3PH 50000TL-60000TL-V1
Rev. 1.1 15/03/2021
• Labels on the inverter
Figure 6 – Do not remove the label on the side of the inverter
2.2.
Description of functions
The DC voltage generated by the PV modules is filtered through the input board before entering the power
board. The input board also has the function of detecting the insulation impedance and the DC input
voltage/current. The power board converts the DC power into AC power. The current converted into AC is
filtered through the output board and is then fed into the grid. The output board also has the function of
measuring the grid and GFCI voltage/current and acts as an output insulation relay. The control board
provides the auxiliary power supply, controls the operating status of the inverter and shows it on the
display. The display also shows the error codes when the inverter is not functioning properly. At the same
time, the control board can activate the protection relay in order to protect the internal components.
Operating principles
The control board of the strings measures the input current and voltage, analyses the functioning
state of each PV string, and if anomalies are found on the strings, alerts the user to perform the
relative control and maintenance operations.
The DC switch disconnects the internal circuits from the DC input for maintenance purposes.
DC surge arresters (category III, category II added on models S4 and S5) provide overvoltage
discharge on the DC side to protect the inverter’s internal circuits against excessive DC voltages.
Electromagnetic filters (EMI) at the input and output filter the electromagnetic emissions of the
inverters to ensure that they meet the electromagnetic compatibility requirements.
The input board measures the insulation impedance, voltage and current of the various strings; it
also manages the algorithm of the maximum power point algorithm (MPPT) to maximum the power
generated by the photovoltaic strings.
