SMA SB 1100LV - Manual (Page 16)

Installation requirements SMA Technologie AG
Page 16 SB1100LV-11:SE2006 Installation Guide
Rating for a line circuit breaker in a photovoltaic electrical power unit
operated in parallel with the low-voltage grid
Various factors should be taken into account when selecting line circuit breakers. These
include, for example:
•
The type of cable used (conductor material and insulation)
• Ambient temperatures affect the cables (higher temperatures result in a reduced
maximum current load)
• Method of routing the cable (reduces the ampacity of the conductor)
• Bundling cables together (reduces the ampacity of the conductor)
• Loop impedance [Z] (in the event of a body contact this limits the current that can
flow and therefore determines the response behavior of the circuit breaker)
• Sufficient distance between the circuit breakers so as to avoid undue heating (heat
can trigger the circuit breakers early).
• Selectivity
• Protection class of the connected load (VDE 0100, part 410, Protection against
electric shock)
The following standards should be followed in all cases:
•
DIN VDE 0298-4 (Cable routing and current-carrying capacity)
• DIN VDE 0100; part 430 (Protective measures; protection of cable and cords
against overcurrent)
• DIN VDE 0100; part 410 (Protective measures; protection against electric
shock)
Attention!
We recommend using a 16 A line circuit
breaker to protect the power circuit. No
loads should be connected to this power
circuit.
Please pay attention to chapter 11 "Rating for a line circuit breaker" (Page 51).