Ex p control unit
Motor purge controller
Safety
Rev. 0
01-37A2-7D0003_Operating instructions_MPC_20210923_0_en.docx
Page 19 of 96
Safety values
THE FOLLOWING SAFETY VALUES ARE WITHOUT OPTIONAL
SENSORS.
The optional sensors must be considered to determine the total
failure rate!
The safety values can be found in the documentation for
the optional sensors used.
Safety values in accordance with IEC/EN 61508 / DIN EN ISO 13849-:
SIL = 2
Performance level: = d
PFH
sys
= (PFH_S+PFH_C) = 1,70E-08
HFT = 1
SFF
sys
= 92,85 %
MTTFd = 76 Yr
DC = 88,78 %
Device type B (complex equipment)
Repeat test interval = 1 year
Category 3
Response time
The reaction time of the Ex p control unit APEX to safety-relevant functions,
without specific user delay times, is less than 2 seconds.
With the Ex p control unit APEX, it is possible to set a delay time in the event of
pressure fluctuations below the minimum pressure.
This results in a delay time of
T
reaction
=
T
control
+ T
delay
T
reaction
=
Time until the Ex p APEX control unit reacts to a safety-relevant
function
T
control
=
Internal time that the Ex p control unit needs to recognise the
safety-relevant triggering. <2 seconds
T
delay
=
Adjustable delay time for safety-relevant releases which is
added to the response time T
control
.
Residual risk
Residual risks can arise from:
Errors in the configuration
Errors in the operation
Errors in the wiring
