Hi,
I'd like to know the purpose of MOS (maintenance override
switch). At site, these switches are installed in a
stanchion with the transmitter (connected to ESD). thank
you.
Answers were Sorted based on User's Feedback
maintenance override function is used for bypassing shutdown
processing so that it is not executed by safety logic during
partial maintenance such as specific input.Creating bypass
logic using a dedicated override allows the (HIS) to safely
perform maintenance override for SCS (system control station)
However Maintenance override can not executed from the HIS
unless this switch is in the permission status.
Is This Answer Correct ? | 22 Yes | 0 No |
Answer / seba
MOS is used for enabling /disabling (permision to bypasing
shutdown signal from ESD system.once it enabled you can
overide perticular loop or swtich or function block.
MOS is installed normally on DCS and activating by DCS
operator or concerned engineer for allowing maintenance
technician to perform calibration or replacement of faulty
switches and transmitters.
sebalukose@gmail.com
Is This Answer Correct ? | 20 Yes | 2 No |
Answer / winter r
I want a example defeat of control sheet about when
something is verride .
Is This Answer Correct ? | 1 Yes | 2 No |
We do have a problem in the company that is one PT connected to PlC which is mean 1 out of 1 in PLC system we do have the PAHH is 55 mbar and PALL 8 mbar with a timer of 15 sec for the PAHH the problem started when PAHH goes more than the set point which is 55 it reached up to 71 but due to timer doesn't trip . We force it and we checked everything nothing there . We replaced the transmitter problem still there the reading goes more than the 55 bar the range for transmitte is 0- 60 mbar . So we did loop check , aculaizing valve , wiring all are okay . What the possible causes for this ???
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