SMA SUNNY BOY 1700, Installation Manual

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Installation requirements SMA Technologie AG
Page 16 SB1700-11: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 defines the response behaviour of the circuit breaker)
• Adequate clearance between the circuit breakers in order to avoid excessive
heating (automatic circuit breakers trip earlier when they are warmer)
• Selectivity
• Protection class of the connected load (VDE 0100, part 410), Protection against
electric shock
The following standards
1
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)
We recommend using a 16 A line circuit
breaker to protect the power circuit. No
loads should be connected to this power
circuit.
Please have a look at chapter 9 "Rating for a line circuit breaker" (page 39).
1. The standards mentioned above are to be only used as a guideline for your
installation. They apply for installations in Germany. Please note that other
standards will apply for different countries throughout the world.