We have a simplex Mark-V panel on a GE frame 5 turbine. The panel was powered off during a shutdown and after power-on the following message appeared

0000 Diagnostic Alarm <C> <Q>

Can anyone shed some light on the possible reasons for this alarm and in which manual can i find any information related to this alarm.

The turbine is running at the moment, is there any way to resolve the problem online?

Also comment on whether can I keep the turbine running under this alarm condition

Thanks

 

On a Mark V Speedtronic turbine control panel being operated with an <I> operator interface, this Process Alarm is a notification to the operator to look at the Diagnostic Alarm Display to see what Diagnostic Alarm condition(s) has(have) been detected and is being annunciated. Diagnostic Alarms can be acknowledged and reset from targets at the bottom of the Diagnostic Alarm Display after they have been resolved.

On a Mark V Speedtronic turbine control panel being operated with an GE Mark V HMI operator interface, this Process Alarm is also a notification to the operator that a Diagnostic Alarm condition has been detected. Most GE Mark V HMIs are configured to be able to display Diagnostic Alarms in the same window or display that Process Alarms are shown in. However, that can be changed by manipulating the Alarm Setup, and some very early GE Mark V HMIs did have a separate Diagnostic Alarm Display.

When all Diagnostic Alarms have been resolved and reset by the operator, the Process Alarm Drop 0000 can then be reset from the Process Alarm display.

As a *GENERAL* rule, most Diagnostic Alarms will not prevent a unit from running, or, as you've noted, from being started. However, every Diagnostic Alarm condition should be investigated and resolved, as they are indications that something is amiss with the control panel hardware or software. By monitoring Diagnostic Alarm conditions, some trip conditions can be prevented or anticipated.

But as a general rule, most people just ignore Diagnostic Alarms, because, as you've seen the unit will continue to run with them and if the unit is running most people just ignore them. Worse, there really is no good troubleshooting information for most Diagnostic Alarms and the messages can be very cryptic and even misleading in some cases.

I could count on one finger the number of times people have provided Diagnostic Alarm information when asked to for help in troubleshooting their problems. Because most Diagnostic Alarms can't be understood and because the unit continues to run with them unacknowledged and unresolved, no one ever really pays proper attention to them, until after the fact when someone (*if* someone) looks at the Diagnostic Alarms which were present before a trip and realizes, "Oh! That's what that meant!"

 

I have only one comment that CSA did not mention.

Occasionally the P0 Diagnostic alarm will latch. Once all diagnosic alarms have been cleared, the process alarm 0 will remain.

Check the alarms.lst file for the proper logic point for alarm 0. It is usually L30DIAG_C. It can then be forced from logic forcing display to clear the process alarm 0. I have have performed this on operating turbines.

 

Thanks, CTTech. I had forgotten this one.

When this happens, one can usually go to the LCC/SLCC displays and 'Clear Sys Errors' from the keypad on all the processors and the alarm will go away. There were a couple of PROM revisions that didn't reset all Diagnostic Alarms properly, but clearing them from the LCC/SLCC displays usually worked when it seemed that the alarm was "latched."