Siemens SIPART PS2 PA 6DR55 Series, Руководство по эксплуатации

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Functional safety
8.2 Device-specific safety notes
SIPART PS2 with PROFIBUS communication
Operating Instructions, 09/2007, A5E00127926-07
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8.2.5 Maintenance/Checking
Checking the function
We recommend that the functioning of the positioner is checked at regular intervals of one
year.
Checking safety
You should regularly check the safety function of the entire safety circuit in line with IEC
61508/61511. The testing intervals are determined during the calculation for each individual
safety circuit in a system (PFD
AVG
).
The following tests are particularly relevant for the SIPART PS2 PA and SIPART PS2 FF
positioners and are to be carried out:
1.
Inspection of the safety shutdown
–
Apply a LOW signal, i.e. a voltage less than 4.5 V, at the input for the safety shutdown
– Check whether the valve moves to the safety position.
2. Inspection of the actuator behavior
–
Apply a HIGH signal, i.e. a voltage more than 13 V, at the input for the safety
shutdown
– Set the nominal value to 50% either by using the local operation (manual operation),
the PROFIBUS PA or the FOUNDATION field bus communication
– Reduce the inlet pressure (P
z
) to a third of the maximum supply pressure
– Check whether the valve moves to the safety position.
3. Check the filters in the pneumatic connections for contamination and clean them if
necessary.
8.2.6 Safety characteristics
The safety characteristics necessary for using the system are listed in the SIL declaration of
conformity (see "Appendix A"). These values apply under the following conditions:
●
The positioner is only used in applications with a low demand rate for the safety function
(low demand mode).
● The coding bridge on the basic electronic system was plugged on to the left position
facing the terminals ("safe pos.") or removed completely.
● The positioner is blocked against unwanted and unauthorized changes/operation.
● The shut-off signal for the SIPART PS2 PA and SIPART PS2 FF positioners is generated
at the input for the safety shutdown (terminals 81 and 82) by a safe system which meets
at least SIL2. The LOW level has a maximum of 4.5 V at the input terminals.