BECKHOFF TwinSAFE - Manual (Page 85)

Circuit examples
Application Guide TwinSAFE 83
as:
1
ܯܶܶܨ
ௗ ௧௢௧
ൌ
1
ܯܶܶܨ
ௗ
ሺܵܿܽ݊݊݁ݎሻ
൅
1
ܯܶܶܨ
ௗ
ሺܧܮ1904ሻ
൅
1
ܯܶܶܨ
ௗ
ሺܧܮ6900ሻ
൅
1
ܯܶܶܨ
ௗ
ሺܧܮ2904ሻ
൅
1
ሺܯܶܶܨ
ௗ
ሺܭ1ሻሻ
with:
ܯܶܶܨ
ௗ
ሺK1ሻ ൌ
ܤ10
ௗ
ሺܭ1ሻ
0.1 כ ݊
௢௣
If only PFH values are available for EL1904 and EL6900, the following estimation applies:
ܯܶܶܨ
ௗ
ሺELxxxxሻ ൌ
ሺ1 െ ܦܥሺܧܮݔݔݔሻሻ
ܲܨܪሺܧܮݔݔݔሻ
Hence:
ܯܶܶܨ
ௗ
ሺEL1904ሻ ൌ
൫1 െ ܦܥሺܧܮ1904ሻ൯
ܲܨܪሺܧܮ1904ሻ
ൌ
ሺ1 െ 0.99ሻ
1.11E െ 09 ଵ
୦
כ 8760 ୦
୷
ൌ
0.01
9.72E െ 06 ଵ
୷
ൌ 1028.8y
ܯܶܶܨ
ௗ
ሺEL6900ሻ ൌ
ሺ1 െ ܦܥሺܧܮ6900ሻሻ
ܲܨܪሺܧܮ6900ሻ
ൌ
ሺ1 െ 0.99ሻ
1.03E െ 09 ଵ
୦
כ 8760 ୦
୷
ൌ
0.01
9.02E െ 06 ଵ
୷
ൌ 1108.6y
ܯܶܶܨ
ௗ
ሺEL2904ሻ ൌ
ሺ1 െ ܦܥሺܧܮ2904ሻሻ
ܲܨܪሺܧܮ2904ሻ
ൌ
ሺ1 െ 0.99ሻ
1.25E െ 09 ଵ
୦
כ 8760 ୦
୷
ൌ
0.01
1.1E െ 05 ଵ
୷
ൌ 913.2y
ܯܶܶܨ
ௗ
ሺScannerሻ ൌ
൫1 െ ܦܥሺܵܿܽ݊݊݁ݎሻ൯
ܲܨܪሺܵܿܽ݊݊݁ݎሻ
ൌ
ሺ1 െ 0.90ሻ
7.67E െ 08 ଵ
୦
כ 8760 ୦
୷
ൌ
0.1
6.72E െ 04
ଵ
୷
ൌ 148.8y
MTTF
d tot
=
ଵ
భ
భరఴ.ఴ೤
ା
భ
భబమఴ.ఴ೤
ା
భ
భభబఴ.ల೤
ା
భ
వభయ.మ೤
ା
భ
ఱఴఴ.ళ೤
ൌ 87.8ݕ
DC
avg
=
వబ%
భరఴ.ఴ
ା
వవ%
భబమఴ.ఴ
ା
వవ%
భభబఴ.ల
ା
వవ%
వభయ.మ
ା
వవ%
ఱఴఴ.ళ
ା
వవ%
ఱఴఴ.ళ
భ
భరఴ.ఴ
ା
భ
భబమఴ.ఴ
ା
భ
భభబఴ.ల
ା
భ
వభయ.మ
ା
భ
ఱఴఴ.ళ
ା
భ
ఱఴఴ.ళ
ൌ 94.38%
Notice
Category
This structure is possible up to category 3 at the most through the use of the type 3
(category 3) laser scanner.