ABB 2600T-Serie Bedienungsanleitung Seite 24

8.18 Proof tests
Safe undetected faults could occur during the operation of the
transmitters. These failures do not affect the transmitter
operations.To maintain the claimed Safety Integrity Level (SIL 2)
a proof test procedure is requested every 10 years.
The proof tests consist in the following operations:
— Switch off the device.
— Assure that the Write Protect Mode switch is in Write
Protect condition.
— Power-on the transmitter: the transmitter performs
automatically a self-test that consists in the operations
below:
ROM test
RAM test
Test of the analog output stage and of the feedback
A/D converter
Test of the power supply voltage
Non volatile memory test
— Apply pressure up to 50% of the calibrated range and
check the output value. It shall be within the stated safety
accuracy (2% of sensor range).
In case the tests would fail the transmitter will drive the output
to the alarm values. In this case a correction action consists in
the re-calibration of the D/A converter. In case the normal
functionality will be not re-established, the transmitter shall be
considered failed and not possible to use.
266DXX, 266VXX,
266PXX, 266HXX,
266NXX
λ
dd 2,62E-07
λ
du 6,82E-08
λ
3,37E-07
sd
λ
3,01E-07
su
HFT 0
T1
SFF 92,95%
Total Failure Rate
9,68E-07
MTBF 118
MTTR
D: 79%
DC
C: 53%
PFD (1 year)
2,99E-04
PFH (1 year) 6,82E-08
PFD (10 years)
2,98E-03
PFH (10 years) 6,82E-08
Testing time < 20 s
ROM check time < 30 s
24 SOI/266-XC Rev. D | 2600T Series Pressure transmitters
8.19 Safety-related parameters
The Safety 266 pressure transmitters product meets the SIL2
requirements of IEC 61508 in low as well as high demand
mode of operation. The total PFD in low demand mode for 10
years proof test interval in the worst case is less than the 15%
of the range defined in IEC 61508-1.
The relevant numbers are stated in the table below.
266MXX, 266CXX, 266MXX, 266CXX,
266JXX, 266RXX 266JXX, 266RXX
(range R) (except range R)
4,11E-07 3,94E-07
6,87E-08 6,85E-08
2,45E-07 2,39E-07
3,55E-07 3,53E-07
0 0
1 year / 10 years (8760h / 87600h)
93,63% 93,51%
1,08E-06 1,06E-06
106 108
D: 86% D: 85%
C: 41% C: 40%
3,01E-04 3,00E-04
6,87E-08 6,85E-08
3,00E-03 2,99E-03
6,87E-08 6,85E-08
< 20 s < 20 s
< 30 s < 30 s
266GXX, 266AXX
(except range C and F)
4,05E-07
6,85E-08
2,40E-07
3,42E-07
0
93,51%
1,06E-06
108
8 hours
D: 86%
C: 41%
3,00E-04
6,85E-08
2,99E-03
6,85E-08
< 5 s
< 30 s
8 Safety manual
266GXX, 266AXX
(only range C and F)
4,13E-07
6,90E-08
2,40E-07
3,18E-07
0
93,37%
1,04E-06
110
D: 86%
C: 43%
3,02E-04
6,90E-08
3,01E-03
6,90E-08
< 70 s
< 70 s