SMA Sunny Boy SB 1100LV, Installation Manual, Page: 28 / 62

Installation SMA Technologie AG
Page 28 SB1100LV-11:SE2006 Installation Guide
causes reverse current to flow through the faulty generator string that, depending on the
amount of current, may lead to excessive heating or destruction of the modules in this
string.
Among other symptoms, the following faults may lead to reduction of the open circuit
terminal voltage of a generator string and subsequent reverse current in parallel-
connected systems:
•
Short circuit in one or more modules,
• Short circuit in one or more cells in a module,
• Double ground fault in a module and/or the cabling.
Despite the fact that these faults are very unlikely, and extremely rare in practice,
preventative measures must still be taken. After all, these types of faults carry a high
potential for damage and danger, since all modules in the affected string may be
damaged and the local heating may also cause secondary damage.
Current in the faulty string =
Total current of the remaining strings