PFDavg, PFH values for HF-CPUs
Below you will find the probability of failure values (PFDavg, PFH values) for the HF-CPUs with
a service life of 20 years and with a repair time of 100 hours:
Operation in low demand mode
low demand mode
According to IEC 61508:2010:
PFDavg = Average probability of dangerous
failure on demand
Operation in high demand or continuous mode
high demand/continuous mode
According to IEC 61508:2010:
PFH = Average frequency of a dangerous
failure [h
-1
]
< 2E-05 < 1E-09
15.5 Information on insulation tests, protection class, degree of
protection and rated voltage
Insulation
The insulation is designed in accordance with the requirements of IEC61010-2-201.
NOTE
For modules with 24VDC (SELV/PELV) supply voltage, electrical isolation is tested with
707VDC (type test).
Pollution degree/overvoltage category in accordance with IEC61131-2, IEC61010-2-201
•
Pollution degree 2
•
Overvoltage category: II
Protection class according to IEC61131-2, IEC61010-2-201
The S7-1500R/H redundant system meets protection class I requirements and parts of
protection classes II and III.
Degree of protection IP20
Degree of protection IP20 in accordance with IEC60529 for all modules of the S7-1500R/H
redundant system:
•
Protection against contact with standard test fingers
•
Protection against foreign objects with diameters in excess of 12.5 mm
•
No protection against water
364
S7-1500R/H redundant system
System Manual, 11/2022, A5E41814787-AD
Technical specifications
15.5 Information on insulation tests, protection class, degree of protection and rated voltage