SFFS422 May 2022
| Standard | Title |
|---|---|
| IEC 61800-5-2 | Adjustable speed electrical power drive systems – Part 5-2: Safety requirements – Functional |
| IEC 61508 | Functional safety of electrical/electronic/programmable electronic safety-related systems |
| ISO13849-1/2 |
Safety of machinery -- Safety-related parts of control systems -- Part 1: General principles for design, --- Part 2: Validation |
| IEC 60204-1 | Safety of machinery - Electrical equipment of machines - Part 1: General requirements |
| IEC 62061 | Safety of machinery - Functional safety of safety-related electrical, electronic and programmable electronic control systems(1) |
| Acronym | Description |
|---|---|
| DC | Diagnostic coverage |
| FIT | Failure in time (1-e9/hour) |
| HFT | Hardware fault tolerance |
| MTTF | Mean time to failure (per year) |
| MTTFd | Mean time to failure – dangerous (per year) |
| PFD | Probability of dangerous failure |
| PFH | Average frequency of a dangerous failure of the safety function [per hour] |
| SFF | Safe failure fraction |
| PDS/SR | Power drive system, safety related |
| DFD | Dangerous failure detected. Acronym used on the FMEA tables |
| DFU | Dangerous failure not detected. Acronym used on the FMEA tables |
| SF | Safe failure |
| NEF | No effect failures, failures which don’t have an impact on the safety function. Acronym used in FMEA tables. |
| FRT | Fault response time |
| DTI | Diagnostics time interval |