ABB ACH480, Hardware Manual

Page: 195 / 214

Safety data
The safety data for the Safe torque off function is given below.
Note: The safety data is calculated for redundant use, and does not apply if both STO
channels are not used.
TM
(a)
CCF HFT SC Cat.
DC
(%)
MTTFD
(a)
PFDavg
(T1 = 5
a)
PFDavg
(T1 = 2
a)
PFH
(T1 = 20
a)
(1/h)
SFF
(%)
PL
SIL/
SILCL
Frame
size
3-phase U
N = 400/480 V
20 80 1 3 3 ≥90 2568
1.67E-
04
6.68E-
05
8.00E-
09
>90 e 3 R1
20 80 1 3 3 ≥90 2568
1.67E-
04
6.68E-
05
8.00E-
09
>90 e 3 R2
20 80 1 3 3 ≥90 2569
1.67E-
04
6.68E-
05
8.00E-
09
>90 e 3 R3
20 80 1 3 3 ≥90 2568
1.67E-
04
6.68E-
05
8.00E-
09
>99 e 3 R4
3AXD10000320081 D
• The following temperature profile is used in safety value calculations:
• 670 on/off cycles per year with Δ T = 71.66 °C
• 1340 on/off cycles per year with Δ T = 61.66 °C
• 30 on/off cycles per year with Δ T = 10.0 °C
• 32 °C board temperature at 2.0% of time
• 60 °C board temperature at 1.5% of time
• 85 °C board temperature at 2.3% of time.
• The STO is a type A safety component as defined in IEC 61508-2.
• Relevant failure modes:
• The STO trips spuriously (safe failure)
• The STO does not activate when requested
• A fault exclusion on the failure mode “short circuit on printed circuit board” has
been made (EN 13849-2, table D.5). The analysis is based on an assumption
that one failure occurs at one time. No accumulated failures have been analyzed.
• STO response times:
• STO reaction time (shortest detectable break): 1 ms
• STO response time: 5 ms (typical), 15 ms (maximum)
• Fault detection time: Channels in different states for longer than 200 ms
• Fault reaction time: Fault detection time + 10 ms
• Indication delays:
The Safe torque off function 195