Sample application
ID 442181.07
22
Operating manual ASP 5001
6
WE KEEP THINGS MOVING
6.3
Result
6.3.1
DC = 60 % for Ta1
The failure probability for the safety-relevant part of the inverter with DC = 60 % for T1a was determined to
be PFH
d
= 3.47
10
-9
h
-1
. This corresponds to a SIL 2 according to DIN EN 61800-5-2 considering the
structural limitations of the architecture. In this way, 0.35 % of PFH
d
is used by SIL 2.
The relationship between PL and SIL is taken from table 4 of DIN EN ISO 13849-1. SIL 2 in a high/continual
operating mode corresponds to a PL d according to this table. The requirements of category 3 with regard to
the minimum requirements for DC
avg
, MTTF
d
and CCF are also met.
For the complete STO and SS1 safety function as it is described in the relevant application example, a failure
probability of PFH
d
= 3.04
10
-8
h
-1
is determined. This also corresponds to a PL d or SIL 2.
6.3.2
DC = 90 % for Ta1
The failure probability for the safety-relevant part of the inverter with DC = 90 % for T1a was determined to
be PFH
d
= 2,61
10
-9
h
-1
. This corresponds to a SIL 3 according to DIN EN 61800-5-2 considering the
structural limitations of the architecture. In this way, 2,61 % of PFH
d
is used by SIL 3.
The relationship between PL and SIL is taken from table 4 of DIN EN ISO 13849-1. SIL 3 in a high/continual
operating mode corresponds to a PL e according to this table. The requirements of category 3 with regard to
the minimum requirements for DC
avg
, MTTF
d
and CCF are also met.
For the complete STO and SS1 safety function as it is described in the relevant application example, a failure
probability of PFH
d
= 2.96
10
-8
h
-1
is determined. This also corresponds to a PL e or SIL 3.
