Pilz PMCprotego S1--2, Operating Manual

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Technical details
Operating Manual PMCprotego S1­2(­C)
1002528­EN­03
89
9.1.1.2 MTTF >= 57 years
Operating
mode
EN ISO
13849­1:
2008
PL
EN ISO
13849­1:
2008
Category
EN 62061
SIL CL EN 62061
PFH
D
[1/h]
IEC 61511
SIL IEC 61511
PFD EN ISO
13849­1:
2008
T
M
[year]
Safe actu­
ator with
motor en­
coder, MTTF
≥ 57 years
PL e Cat. 4 SIL CL 3 2,65E­08 SIL 3 4,94E­04 20
The characteristic data is valid when using a motor encoder with an MTTF ≥ 57 years.
The motor encoder is already included in the characteristic data, so no more calculations
need to be performed for the "Safe Actuator" subsystem.
Subsystem
Safe actuator
PMCprotego D
PMCprotego S1
Motor encoder with MTTF
³
57 years
The safety­related characteristic data is valid for all safety functions.
All the units used within a safety function must be considered when calculating the safety
characteristic data.
9.1.2 Safe actuator with two encoders
Operating
mode
EN ISO
13849­1:
2008
PL
EN ISO
13849­1:
2008
Category
EN 62061
SIL CL EN 62061
PFH
D
[1/h]
IEC 61511
SIL IEC 61511
PFD EN ISO
13849­1:
2008
T
M
[year]
Safe actu­
ator
PL e Cat. 4 SIL CL 3 1,46E­08 SIL 3 4,72E­04 20
The safety analysis of the plant or machine may necessitate a second encoder (external
encoder). Example: Fault detection in the mechanical transmission path between motor and
process.
The sensor subsystem consists of the motor encoder (sensor 1) and an external encoder
(sensor 2). A separate PL or SIL must be calculated for this subsystem. For this subsystem
structure, Category 3 with a DC of 99 % is acceptable. The following characteristic data is
required for both sensors (motor encoder and external encoder): MTTF
d
and λ
d
/λ.