Sto Technical Data - Danfoss VLT Midi Drive FC 280 Operating Instructions Manual

Safe Torque Off (STO)

6.5 STO Technical Data

The Failure Modes, Effects, and Diagnostic Analysis (FMEDA) is performed based on the following assumptions:
•
FC 280 takes 10% of the total failure budget for an SIL2 safety loop.
•
Failure rates are based on the Siemens SN29500 database.
•
Failure rates are constant; wear-out mechanisms are not included.
•
For each channel, the safety-related components are considered to be of type A with a hardware fault tolerance
of 0.
•
The stress levels are average for an industrial environment and the working temperature of components is up
to 85 °C.
•
A safe error (for example output in safe state) is repaired within 8 hours.
•
No torque output is the safe state.
Safety standards
Safety function
Safety performance
1)
Reaction time
Table 6.3 Technical Data for STO
1) Reaction time is the amount of time from an input signal condition that triggers the STO until the torque is off on the motor.
2) The way to perform proof test please refer to chapter 6.4 Maintenance and Service for STO.
MG07A102
Operating Instructions
Safety of Machinery
Functional Safety
Safe Torque Off
ISO 13849-1
Category
Diagnostic Coverage (DC)
Mean Time to Dangerous Failure
(MTTFd)
Performance Level
IEC 61508/IEC 61800-5-2/IEC 62061
Safety Integrity Level
Probability of Dangerous Failure per
Hour (PFH) (High Demand Mode)
Probability of Dangerous Failure on
Demand (PFD for PTI = 20 years)
avg
(Low Demand Mode)
Safe Failure Fraction (SFF)
Hardware Fault Tolerance (HFT)
2)
Proof Test Interval
Common Cause Failure (CCF)
Diagnostic Test Interval (DTI)
Systematic Capability
Input to output response time
Danfoss A/S © 11/2015 All rights reserved.
ISO 13849-1, IEC 62061
IEC 61508
IEC 61800-5-2
Cat. 3
60% (Low)
2400 years (High)
PL d
SIL2
7.54E-9 (1/h)
6.05E-4
> 84%
1 (Type A, 1oo2D)
20 Years
β = 5%; β = 5%
D
160 ms
SC 2
Enclosure sizes K1–K3: Maximum 50 ms
Enclosure sizes K4 and K5: Maximum 30 ms
6 6
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