SMA Solar Technology SUNNY BOY 3.0, Operating Manual, Page: 31 / 100

6.6 DC Connection
6.6.1 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 (see Section 14 "Technical Data", page 89).
☐ The thresholds for the input voltage and the input current of the inverter must be adhered to
(see Section 14 "Technical Data", page 89).
☐ 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).
Use of Y adapters for parallel connection of strings
The Y adapters must not be used to interrupt the DC circuit.
• Do not use the Y adapters in the immediate vicinity of the inverter. The adapters must not
be visible or freely accessible.
• In order to interrupt the DC circuit, always disconnect the inverter as described in this
document (see Section 10, page 60).
6.6.2 Assembling the DC Connectors
For connection to the inverter, all PV module connection cables must be fitted with the DC
connectors provided. Assemble the DC connectors as described in the following. Be sure to observe
the correct polarity. The DC connectors are marked with the symbols "+" and "−".
Figure 7: Negative (A) and positive (B) DC connectors
6 Electrical Connection SMA Solar Technology AG
Operating Manual 31 SB30-50-1AV-40-BE-en-10