Requirements for the DC Connection

Requirements for the PV modules per input:

  • All PV modules must be of the same type.
  • All PV modules must be aligned and tilted identically.
  • On the coldest day based on statistical records, the open-circuit voltage of the PV array must never exceed the maximum input voltage of the inverter.
  • The same number of series-connected PV modules must be connected to each string.
  • The maximum input current per string must be maintained and must not exceed the through-fault current of the DC connectors ( > Technical Data).
  • The thresholds for the input voltage and the input current of the inverter must be adhered to ( > Technical Data).
  • The positive connection cables of the PV modules must be fitted with the positive DC connectors (for information on assembling DC connectors, see the DC connector installation manual).
  • The negative connection cables of the PV modules must be fitted with the negative DC connectors (for information on assembling DC connectors, see the DC connector installation manual).
  • If the inverter is not equipped with an ESS and the regulations in the country of installation require an external DC load-break switch, you must install an external DC load-break switch.

Use of Y adapters for parallel connection of strings

The Y adapters must not be used to interrupt the DC circuit.

  1. Do not use the Y adapters in the immediate vicinity of the inverter. The adapters must not be visible or freely accessible.
  2. In order to interrupt the DC circuit, always disconnect the inverter as described in this document ( > Disconnecting the Inverter from Voltage Sources).

Reduced electromagnetic compatibility of the inverter in case of incorrect DC connection

If the positive terminal and the negative terminal of a string are not connected to the same input, electromagnetic compatibility of the inverter cannot be guaranteed. As a result, the inverter can cause electromagnetic interference in other devices.

  1. Always connect the positive terminal and the negative terminal of one string to the same input.
    <  DC Connection
    >  Connecting the PV Array