Rating for a line circuit breaker
SMA
Technologie AG
Page 40
SB2500-11:SE2006
Installation Guide
For example, one manufacturer's circuit breaker may be designed for an ambient
temperature of 50 °C.
Load factors according to data sheet specifications:
• Reduction through permanent load >1h = 0.9
1
• Reduction when 9 circuit breakers are arranged side-by-side without gaps =
0.77
2
• Increase in nominal current as a result of ambient temperatures of 40 °C in the
circuit breaker panel = 1.07
3
Result:
The nominal load current for the line circuit breaker is calculated as:
Ibn = 10 A x 0.9 x 0.77 x 1.07 = 7.4 A
Example for the thermal selection of a 10 A line circuit breaker with B sensitivity
with no gap between the circuit breakers:
1. Permanent loads of longer than 1 hour are possible in photovoltaics.
2. When only one circuit breaker is used, this factor = 1
3. Because the circuit breakers are rated for 50 °C
Summary of Contents for SUNNY BOY 2500
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Page 6: ...Table of Contents SMA Technologie AG Page 6 SB2500 11 SE2006 Installation Guide ...
Page 8: ...Foreword SMA Technologie AG Page 8 SB2500 11 SE2006 Installation Guide ...
Page 10: ...Safety information SMA Technologie AG Page 10 SB2500 11 SE2006 Installation Guide ...
Page 38: ...Replacing the varistors SMA Technologie AG Page 38 SB2500 11 SE2006 Installation Guide ...
Page 44: ...Contact SMA Technologie AG Page 44 SB2500 11 SE2006 Installation Guide ...
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