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Master Protective Lockout and No Ready to Start
Master protective lockout alarm and no ready to start in GE Mark-IV.
By Sanjay Mallik on 6 July, 2019 - 2:17 pm
0 out of 1 members thought this post was helpful...

We have a problem in GE mark-IV control system in frame 9 gas turbine. There was not ready to start due to master protective lockout. There was voting mismatch for so many parameter, and we didn't find any clue. But after several hours after master resetting, we get ready to start and master protective lockout doesn't appear any more. But when turbine started, it again appear.

Please give us some idea what are the parameter do we need to monitor to resolve the problem.

Thanking you

2 out of 2 members thought this post was helpful...

You must have some other Alarm together with the "Master Protective Lockout". I find it nearly impossible to believe that that was the only Alarm.

Please help and we can try and help with your problem.

1 out of 1 members thought this post was helpful...

Sanjay Mallik,

The alarm is (or should be) "MASTER PROTECTIVE START-UP LOCKOUT".

This is a technical forum. It helps if you can be specific, instead of just listing what is felt is the "important" part of the Process Alarm message text.

If I recall correctly, "MASTER PROTECTIVE START-UP LOCKOUT" is driven by logic signal L86MP. So you need to look in the Mark IV Speedtronic Elementary and find L86MP and then find out why it's picking up.

You can use the Master Protective Lockout alarm Drop Number and go to the 18 sheets of the Mark IV Speedtronic Elementary and find the Drop number and see which logic signal causes the alarm to be annunciated. And, then go to the proper sheet and find the rung (most likely something like L86MP).

If the Mark IV has Data List 11, Rung Display, you can use the Rung Display and see what the contacts in the rung look like in real time. If there is no Rung Display on the Mark IV, you will have to put each of the contacts of L86MP into the Logic Forcing Display and determine the state of each contact to determine why L86MP is picking up (going to a logic "1") and why it is latching up.

When you see a LOT of Diagnostic Alarms, don't just throw your hands up and throw the towel in. Start looking at the Diagnostic Alarm messages, and which processor is "throwing" (annunciating) the Diag. Alarms and start figuring out why the processor(s) are thinking the unit can't be started.

It's not easy, but it's NOT that difficult, either. It takes some initiative and some thought and critical thinking, but it's doable.

AND, as glenmorangie says--help us to help you. Just because you think someone has experienced this condition before they should be able to tell you straightaway exactly what is causing the problem doesn't mean you are correct. If you want help, you have to be willing to do more than just keep pressing MASER RESET and asking for help using an incomplete Process Alarm message. (Now--I may be wrong about the exact text of the message, but I don't think I am. My apologies if I am wrong, but if I'm not, then you need to provide the entire proper text of the alarm message and at least SOME of the Diagnostic Alarms for us to be of any real help. We can help you--but you need to be specific as this is a technical forum and you are asking technical questions.

By sanjay mallik on 8 July, 2019 - 12:28 pm

In<R> Dignostic alarm status is voting mismatch of: FSRSR, L4X1, L20FGX1, FPRG, L20TVX1, L20VGX, FSRS1, FSR2, FSROUT, FSRACC, FSRSU, S4T4, FSRT, L4QA, L20CBX1

In logic forcing
L4X1 value is <C> 1, <R> 0, <S> 1, <T> 1
FPRG value is <C> 4.78, <R> -1.95, <S> 4.78, <T> 4.78
FSRSR value is <C> 10, <R> -10, <S> 10, <T> 10

and rest of the voting mismatch parameter are same in <c>, <r>, <s> and <t>. At present unit is running, and please give us some idea out the information which i had provided.

thanking you.