The designated safety functions have been designed and tested for functional safety according to the following standards:
IEC 61508:2010
IEC 61800-5-2:2016
ISO 13849-1:2015
IEC 62061:2015
An independent assessment was performed by TÜV NORD.
According to the above listed standards, the figures for the Lexium 62 for using the Inverter Enable are as follows:
|
Standard characteristics |
Variants C/D/G (two‑channel connected, maximum 100 axes) |
Variants C/D/G (single‑channel connected, maximum 200 axes) |
Variants E/F (two‑channel connected, maximum 100 axes) |
|---|---|---|---|
|
SFF (IEC 61508) Safe Failure Fraction |
99% |
99% |
99% |
|
HFT (IEC 61508) Hardware Fault Tolerance |
1 |
1 |
1 |
|
Type (IEC 61508) |
A |
A |
B |
|
SIL (IEC 61508) Safety Integrity Level SILCL (IEC 62061) Safety Integrity Level claim limit |
3 |
2 |
3 |
|
PFH (IEC 61508) Probability of Dangerous Failures per Hour |
0.5*10-9/h |
0.5*10-9/h |
0.95*10-9/h |
|
PL (cat) (ISO 13849‑1) Performance Level (Category) |
e (4) |
d (3) |
e (4) |
|
MTTFd (ISO 13849‑1) Mean Time to Dangerous Failure |
6000 years |
6000 years |
380 years |
|
DC (ISO 13849‑1) Diagnostic Coverage |
99% |
99% |
99% |
|
Lifetime |
20 years |
20 years |
20 years |
|
Maximum reaction time between the request and execution of the designated safety function |
5 ms |
5 ms |
10 ms |
|
Maximum reaction time before the detection of safety-related errors |
5 ms |
5 ms |
10 ms |
|
Maximum reaction time between exceeding the threshold values of extended safety functions and the initiation of substitute reactions |
– |
– |
10 ms |
|
NOTE: The values specified are rounded individually and are therefore not a result of a conversion by for example, PFH in MTTFd or the comparative tables from ISO13849‑1.
|
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In the case of the extended safety functions that can be used with the Lexium 62 variants E/F, the threshold values to be monitored can be adjusted, for example, the limit for safe velocity for the function Safe Limited Speed (SLS). If this value is exceeded, an adjustable substitute reaction is initiated, which is the reason why the previous table includes an additional reaction time.
Additionally, for the Lexium 62 variants E/F, it must be observed that the reliability values depend on the safety functions used since for all position-dependent and velocity-dependent safety functions, the encoder has to be taken into consideration. In turn, the value depends on the encoder type used (see following table). These values are also available as SISTEMA library.
The table shows the standard characteristics for the Lexium 62 variants E/F:
|
Standard characteristics |
Lexium 62 Variant E: MTTFd (ISO 13849-1) Mean Time to Dangerous Failure [years] |
Lexium 62 Variant F: MTTFd (ISO 13849-1) Mean Time to Dangerous Failure [years] |
|---|---|---|
|
Use of SLS, etc |
– |
– |
|
... with Sick Stegmann encoder SKM36 |
250 |
180 |
|
... with Sick Stegmann encoder SKS36 |
250 |
180 |
|
... with Sick Stegmann encoder SRM50 |
190 |
125 |
|
... with Sick Stegmann encoder SRS50 |
200 |
135 |
|
... with Sick Stegmann encoder SEK34 |
210 |
145 |
|
... with Sick Stegmann encoder SEL34 |
200 |
130 |
|
... with Sick Stegmann encoder SEK37 |
245 |
175 |
|
... with Sick Stegmann encoder SEL37 |
245 |
180 |
|
... with Sick Stegmann encoder TTK70 |
95 |
50 |
|
... with Sick Stegmann encoder TTK50 |
80 |
45 |
|
... with Heidenhain encoder ECN113 |
165 |
100 |
|
... but with a separately applied encoder |
320 |
270 |
|
For the sake of clarity, it was assumed for Lexium 62 variant F that both axes use the same encoder type. Contact your Schneider Electric representative for any other calculations. |
||
For Lexium 62 variant F, the specified MTTFd values apply if both axes are being used within one safety function. Thus, there is an arithmetical advantage when using a double drive in a safety function compared to two single drives. If only one axis of a double drive is used in a safety function, the value specified above also has to be used.
Proceed as follows to use an encoder that is not listed in the above table:
|
Step |
Action |
|---|---|
|
1 |
Mount the encoder in accordance with the instructions on encoder assembly. Refer to Setup, Installation and Maintenance. |
|
2 |
Request the MTBF value of the encoder from the encoder manufacturer. |
|
3 |
In the calculation tool, enter:
|
The simplified procedure described above generally leads to conservative results. If the result does not fulfill the requirements from the risk assessment, contact your Schneider Electric representative.