SMA Solar Technology AG
6 Electrical Connection
Installation Manual
STP5-9TL-IA-en-10
39
6.4 DC Connection
6.4.1 Conditions for DC Connection
Requirements for the PV modules per input:
☐ All PV modules must be of the same type.
☐ All PV modules must be aligned identically.
☐ All PV modules must have the same tilt angle.
☐ The maximum input current per string must be maintained and must not exceed the through-fault
current of the DC connectors (see Section 13 "Technical Data", page 90).
☐ The limiting values for the input voltage and the input current of the inverter must be maintained
(see Section 13 "Technical Data", page 90).
☐ At an ambient temperature over 10°C, the open-circuit voltage of the PV modules must not
exceed 90% of the maximum input voltage of the inverter. That prevents the voltage exceeding
the maximum input voltage of the inverter at lower ambient temperatures.
☐ The positive connection cables of the PV modules must be equipped with the positive
DC connectors.
☐ The negative connection cables of the PV modules must be equipped with the negative
DC connectors.
Use of Y Adaptors for Parallel Connection of Strings
The Y adaptors must not be used to interrupt the DC electric circuit.
• Do not use the Y adaptors in close proximity of the inverter. The adaptors may not be
visible or freely accessible.
• Disconnect the inverter from voltage sources only as described in this document
(see Section 10).
