Display and operating elements
VIBROCONTROL 920
VC920E / C102833.002 / V 13
Page 7 / 33
Safety and reliability related values according to DIN EN ISO
13849-1
Safety and reliability related values MTTF, PL and Category according to DIN EN ISO
13849-1 have been evaluated for VIBROCONTROL 920 with the following results:
Parameter
Value (50 °C)
MTTF
922.441 h
~ 105 years
PL
c
Category
1
Test conditions:
♦
Operating temperatures: 50 °C.
♦
Environmental conditions: Ground Benign, Controlled
Note:
The results of this assessment are valid when the following procedures are
followed:
♦
The Relays of the VIBROCONTROL 920 have to be operated in the
„normally energised” mode.
♦
The analog 4-20 mA signal industry-standard current loops must be
used.
♦
The OK Relay has to be used as system function.
♦
The VIBROCONTROL 920 system must be protected against erroneous
change in configuration.
Abbreviations:
MTTF
Mean Time To Failure
PL
Performance Level From PL "a" (highest failure probability) to PL "e"
(lowest failure probability)
Category
Category (CAT)
Classification of the safety related parts of a control system in
respect of their resistance to faults and their subsequent behaviour in
the fault condition, and which is achieved by the structural
arrangement of the parts, fault detection and/or by their reliability.
Ground Benign,
Nearly zero environmental stress with optimum engineering operation
Controlled
and maintenance.
Note:
More detailed information about safety and reliability regarding EN
13849-1 values can be obtained on request from Brüel & Kjær Vibro
(
).