Mark V can't reset

S

Thread Starter

Semutsakti

I have some problem in Mark V..
The turbine can't reset so the MSV and ASV still closed, usually after turbine reset MSV and ASV open.

The alarm that appears in alarm list is
398 ETD FAILED TO RESET IN TIME
399 TRIP/ETD IS STILL LOCKED OUT
340 EMERGENCY TRIP HEADER TRIPPED

it is normal or not if that alarm still exist if the turbine not yet reset??

Can somebody give me clue to solve this problem..
why the turbine can not be reset??
 
It sounds like you may have a hardwired trip that needs to be cleared. I'm just new to Mark V controls, but i had to learn this the hard way. There was a hard wired trip that would lock out when the HRSG drum levels were too low/high. See if the HMI is producing an alarm that say L5E or something with "L5" in it. This is your clue to start looking for hardwired trips. There are a lot of other potential possibilities, but I figure i would share how lessons learned during my frustrations.
 
jpmccros,

Whenever a contact is put into the hardwired trip "string" it is SUPPOSED to have an associated contact which is also wired to a discrete (contact) input of the Mark V to alert the operator the cause of the trip string being tripped. Unfortunately, this practice isn't always adhered to, which can lead to problems such as you describe. I always recommend that sites make a drawing of the inputs in this "string" so that they can, hopefully, remember to check each one when there's a problem like this.

Another issue that can also occur is that the alarm text message may not be very clear. Most sites don't pay any attention to alarms, mostly because of the persistence of nuisance Diagnostic Alarms. But, alarms should be paid attention to, and if the text message isn't clear then it can be edited in ALARM.DAT (the operator interface has to be re-booted to take effect--but ONLY the operator interface; the Mark V does not have to be re-booted if one changes only the text message(s) in ALARM.DAT).

The intent of this string of contacts is to allow a method for tripping the turbine which is independent of the software running in the Mark V. It's almost a "safety relay" function that's built into the <P> core of the Mark V. It's not, prior to popular belief, intended to fool or deceive or trick anyone. The problem, as with a lot of Speedtronic functions and features, is that it's poorly documented. If Speedtronics came with drawings of hardwired inputs and outputs it would also be more helpful, but, as with many things, the I/O get modified in the field and the drawings don't always get marked-up like they should.

Many times, also, people don't realize the E-Stop Pushbutton latches when it's pushed, and has to be manually turned (in the direction of the arrow that's cast into the button's face) to unlatch it to close the contacts. (Believe it or not I've flown thousands of miles to unlatch the E-Stop Pushbutton on more than one occasion.)
 
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