Eaton PKE series Handbuch Seite 50

Motor-protective circuit-
breaker PKE12, PKE32 and
PKE65
46
Average probability of a dangerous failure when the safety
function is on demand (PFD / PFH), using an interval of
36 months for repeat test T1 (maintenance interval:
12 months):
1st demand level F 1/year (low demand mode):
PFD : 5.66 x 10
avg
Requirement for SIL 2 as per standard: f 10
2nd demand level > 1/year (high demand mode):
PFD : 2.56 x 10
avg
Requirement for SIL 2 as per standard: f 10
The mean lifespan between two failures (MTBF) is 74 years.
For the safety-related parts of control systems as per
EN ISO 13849, the following data was determined at an
ambient temperature of 40 °C (functional safety data at
higher ambient temperatures must be requested from the
manufacturer):
Size
Category
Performance Level (PL)
Diagnostic coverage (DC)
2)
MTTF for 40 °C
d
1) The performance level is the result of the risk assessment
based on the percentage of risk mitigation achieved with the
control system's safety-related parts.
2) MTTF is the mean time to a dangerous failure l
d
channel.
Information regarding failure rates at higher ambient
h
temperatures (>
10/15 MN03402004Z-DE/EN
-3
-3
Value
2
1)
d or e
70 %
1.75 x 10
) is available on request.
40 °C
-3 -2
to < 10
-3 -2
to < 10
6
h
for each
du