Safety Characteristics; Maintenance/Check - Siemens SIPART PS2 Operating Instructions Manual

8.5

Safety characteristics

The safety characteristics necessary for use of the system are listed in the SIL declaration of
conformity. These values apply under the following conditions:
● The positioner is only used in applications with low demand rate for the "Low demand mode".
● "Jumper" on the basic electronic system was plugged into the left position facing the
● The positioner is blocked against unwanted and unauthorized changes/operation.
● The shut-off signal for the positioner is generated at the input for the safety shutdown
● The connected actuator must be singe-acting and return the valve to the safe end position
● The air outlet does not contain any additional cross-sectional contractions leading to an
● The restrictor in the Y1 circuit may not be completely closed during operation.
● The auxiliary pneumatic power is free of oil, water and dirt in line with:
● The average temperature viewed over a long period is 40 °C.
● Fault rates are calculated on the basis of a mean time to repair (MTTR) of 8 hours.
● In case of a fault, the pneumatic outlet of the positioner is depressurized. A spring in the
● A dangerous failure of the positioner is when the pressure outlet is not depressurized, or
See also
Settings (Page 142)
8.6

Maintenance/check

Interval
We recommend that the functioning of the positioner is checked at regular intervals of one
year.
SIPART PS2 with PROFIBUS PA
Operating Instructions, 02/2016, A5E00127926-AB
terminals at position "Shut Down enabled" or removed completely.
(terminals 81 and 82) by a safe system which meets at least SIL 2. The LOW level has a
maximum of 4.5 V at the input terminals.
by spring force in the following scenario:
– At a chamber pressure (Y1 connection) up to a third of the maximum available intake
pressure (P connection)
z
increased dynamic pressure. In particular, a silencer is only allowed if icing or other
contamination is ruled out.
DIN/ISO 8573-1, maximum class 2
pneumatic actuator must move the valve to the pre-defined, safe end position.
the safety position is not reached, with a LOW level of maximum 4.5 V at the input for the
safety shutdown.
Functional safety
8.6 Maintenance/check
143