Many alarms appear on diagnostic alarm list about tcea of controller s like (tnh_os ) about 18 alarms.there is a signal cause to power off the tcea of controller s and tnh_os s status =0

the steps which we made are:
1- check all rebons 2-change tcea board

3- change the speed backup from the spare

4-change the cable from front standard to mkv panel for the over speed signal

5-change the termination board tbqa

all above steps we made to fix tnh_os {s} status =0, but from time to time there is a signal going to power off the tcea of controller {s} at {p} core.

i don't know the reason.
please advise me!!!

thanks,

 

untill now there are many alarms at diagnostic alarm list:
dmw, dcur_a, dcure_b, dcur_c dpf,

on controller <s> status =1
PLU ON CONTROLLER <S> POWER OFF
TCEA FOR CONTROLLER <S> POWER OFF
and the status of ( tnh_os ) on controller <s> =0

So , I need to know the reason or how to sove this problem.

thanks,
gsa

 

TNH_OS is the HP shaft speed signal in the <P> core (one for <X>, associated with <R>; one for <Y>, associated with <S>; and one for <Z>, associated with <T>). If you look in the Prevote Data Display you will see the three values for the three protective processors (the TCEA cards in <P>).

The <Y> (<S>) emergency speed pick-up is connected to PTBA-5 and -6 on the <P> core. If TNH_OS is not reading correctly, then it's because something's wrong with the signal connected to PTBA-5 and -6 on the <P> core.

If the <Y> speed signal isn't working and you're running the unit, then <Y> is trying to trip the unit, and <S> is also complaining about the speed error. You have LOTS of alarm, Process- and Diagnostic, that you have poorly communicated to us.

I think you need to get someone to site to help with the problem(s).