SMA SB 1100LV - Manual (Page 53)

SMA Technologie AG Rating for a line circuit breaker
Installation Guide SB1100LV-11:SE2006 Page 53
Summary:
The selected line circuit breaker can be used in our example case since the maximum
current-carrying capacity for fault-free operation is higher than the maximum output
current of the inverter used.
It will not trigger under rated operating conditions!
If the calculated current-carrying capacity of the circuit breaker had been lower than
the maximum output current from the inverter, the following solution might have been
used:
By spacing the circuit breakers at an interval of 8 mm, the reduction factor would be
0.98 instead of 0.77. As a result, the maximum current-carrying capacity would be
9.4 A.
In addition to the thermal rating of the circuit breakers, the boundary conditions as laid
out in section "Rating for a line circuit breaker in a photovoltaic electrical power unit
operated in parallel with the low-voltage grid" (Page 16) and the applicable DIN VDE
standards also need to be taken into account, of course. The main ones that apply here
are:
•
DIN VDE 0100; part 410
• DIN VDE 0100; part 430
• DIN VDE 0298; part 4
In special applications the relevant standards must be followed.