Delta VFD550C43A-00 - The Drive Safety Function Failure Rate

Chapter 17 Safe Torque Off Function | C2000 Plus
17-2
17-1 The Drive Safety Function Failure Rate
Item Definition Standard Performance
SFF Safe Failure Fraction IEC61508
Channel 1: 80.08%
Channel 2: 68.91%
HFT (Type A
subsystem)
Hardware Fault Tolerance IEC61508 1
SIL Safety Integrity Level
IEC61508 SIL 2
IEC62061 SILCL 2
PFH
Average frequency of dangerous failure
[h-1]
IEC61508 9.56×10
-10
PFD
av
Probability of Dangerous Failure on
Demand
IEC61508 4.18×10
-6
Category Category ISO13849-1 Category 3
PL Performance level ISO13849-1 d
MTTF
d
Mean time to dangerous failure ISO13849-1 High
DC Diagnostic coverage ISO13849-1 Low