HI ALL

MARK V TMR under IDOS

ALARM 144: INLET COMPRESSOR PRESSURE DISAGREE.

THE VALUES OF THREE THERMOCOUPLES CT1F1, CT1F2 and CT1F3 ARE 21 C°, 20 C° and 21 C°.
THE VALUE OF CTK1 IS 13.9 C°.

PLEASE HELP ME TO ELIMINATE THIS ALARM.

 

Well, I hope the alarm doesn't read 'Inlet Compressor <i><b>Pressure</b></i> Disagree' because you have provided temperature values, not pressure values....

When did this problem start? After a maintenance outage? After one of the axial compressor inlet temperature sensors was replaced?

What have you done to try to troubleshoot the problem?

What this is telling you is that at least one of the of the sensors providing the indication of the axial compressor inlet temperature not all reading approximately the same value as the others.

To confirm this you need to use the Alarm List file, F:\UNIT1\ALARM.LST, to determine the name of the logic signal that "drives" this alarm. Then you need to use the CSP Cross-reference and the CSP Printout, or the Dynamic Rung Display, to locate the rung where the signal is written to and determine exactly what causes the logic signal to go to a logic "1" and cause the alarm to be annunciated.

Some machines (you didn't say what turbine this is occurring on) have both T/Cs and one, sometimes two, RTDs, sensing axial compressor inlet temperature. I recognize the CTIFn signals, but I don't recognize the CTK1 signal name. I suspect that the CSP is comparing these values, the CTIFn and possibly the CTK1 value, and is telling you that the error is outside of a limit.

If this is the case, then you need to find out why the feedback for CTK1 is lower than the other sensors (again, this is presuming that your investigation of the CSP reveals that, indeed, the CTIFn values and the CTK1 value are being compared and that any difference greater than a setpoint causes this alarm to be generated).

That's about as much help as we can provide without being able to see the Piping Schematics (P&IDs) and CSP and I/O Assignment files for the unit at your site. (The I/O Assignment file, along with the I/O Report file, TC2KREPT.TXT, also located in F:\UNIT1, will help you to locate where the problem input is terminated in the Mark V panel.)

Note that some times these alarms, once resolved, require a 'Master Reset' to be performed to unlatch the alarm. This should be clear from your examination of the CSP or by using Dynamic Rung Display to understand the logic that's driving this alarm.