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Dear CSA and Mk5 experts...

Ours is a GE Fr5 Mk5 I-DOS control turbine. While the turbine is running now, the following Diag.bvAlarms appears:

 
  Diag.drop#  Core    Card   Status   Device
1.   1713       R     TCE1  Logic"1"   SOL1
2.   1697    R-S-T    TCE1     "1"     ETR2(TMR Check Trouble)
3.   1696    R-S-T    TCE1     "1"     ETR1(TMR)
4.   1846       C     "R"      "1"     L4ETR1(voting mismatch)
5.   1847       C     "R"      "1"     L4ETR2 (VMM)
6.    1851        C     "R"    "1"     L12L_acc 
7.    1836       C      "R"    "1"     L12L_P

All the diag.alarms are pertaining to Core"R". Ours is a single shaft turbine.(HP only.) Signals at PTBA for LP speeds are looped. I think, the Trip output of this is also isolated. Will the turbine trip, in case the other TCEA card of "S" OR "T" also sends a false signal to ETR1 OR ETR2 relays for the same problem of L12L signal. How to go about the fault rectification of this Diag. alarm? Now the turbine continues to RUN.

Pls advice... Thanks..

ESKAY,

Yes; the TCEA in Loc. 1 (<X>) is trying to trip the turbine. It's ETR relays are dropped out. If either remaining TCEA drops out it ETRs, then the turbine will trip.

If by "looped" you mean that there is a physical jumper wire between PTBA-3 and -4, and then another jumper between PTBA-7 and -8, and another jumper between PTBA-11 and -12, then that should be all that's required.

It sounds as if you need to replace the TCEA card in Loc. 1 of <P> core. That card is associated with <R>. It's risky business to try replacing the card when the turbine is running without tripping the turbine. The turbine should NOT trip, but there are no guarantees. And without knowing all of the other Diagnostic Alarms and unless you are 100% certain all of the servo-valve coils have the correct polarity of current being applied to them, then it's even riskier.