Subsystem Sb2 - Pilz Intern PMC SR6 Manual

More on safety technology and PMC SR6?
Switching frequency – n
With 365 working days per year, 16 working hours per day and a cycle time of 5 minutes, this
amounts to a respective switching cycle of n
Source: DIN EN ISO 13849-1, Appendix C, Table C.1, calculation: SISTEMA
Mean time to dangerous failure – MTTF
}
B1
MTTF
} B2
MTTF
Calculation: SISTEMA
Probability of a dangerous failure – PFH
B1 and B2
PFH : 2.47 × 10
D
Calculation: SISTEMA
11.3.3.2

Subsystem SB2

Subsystem SB2 is an encapsulated subsystem, i.e. a safety component where the PL, PFH and
category are already specified by the manufacturer.
Subsystem SB2 includes the safety relay K1. The type PNOZ S5 device from Pilz GmbH und Co. KG
serves as a specific example here.
Performance Level – PL, category
}
PL = e
}
Category = 4
Source: Pilz GmbH und Co. KG
Probability of a dangerous failure – PFH
}
Undelayed contacts (STO)
PFH
}
Switch-off delaying contacts (SS1)
PFH
Source: Pilz GmbH und Co. KG
Manual PMC SR6 safety module
1005344-en-US-01
Intern
Information
If the manufacturer does not provide any figure, figures can be taken from
table C.1 in Annex C of DIN EN ISO 13849-1.
op
: 285 years
D
: 143 years
D
-8
-9
= 2.31 × 10 [1/h]
D
-9
= 2.34 × 10 [1/h]
D
= 70080 cycles/year for B1 and B2.
op
D
D
D
Pilz | 38