oussama el,

I want to add: Normally, when GE (USA) provides a 125 VDC battery and charger for a Mark* turbine control there is no ground (earth) detection card in or earth condition detected by the battery charger. Earth detection is performed by the Mark*. Many times, unfortunately, when a Customer with a Mark* buys a new battery charger they mistakenly buy one with earth detection capability--and if the earth detection in the Mark* is not blocked the earth detection of both systems are adversely affected (the business of resistors in parallel reducing the resistance to less than the lowest resistor value). This can cause erroneous earth indications in BOTH the battery charger AND the Mark*. AND it can make locating Earth's very difficult.

It's also VERY IMPORTANT to understand that the earth detection of the Mark* and the battery charger CANNOT distinguish between Earth's in devices connected to the Mark* and other devices powered by the battery--contrsry to false and extremely popular belief. ANY EARTH ON AMY DEVICE OR CIRCUIT CONNECTED OR POWERED BY THE 125 VDC BATTERY IS REPORTED AS AN EARTH BY THE MARK* OR THE BATTERY CHARGER!!! That's right--an earth in the DC Hydraulic Ratchet Pump motor field circuit will be detected by either system as an earth EVEN THOUGH the DC Hydraulic Ratchet Pump motor field circuit is not connected to the Mark*. Same for an earth in the DC Emergency Compartment Lighting circuits. The Mark* ESPECIALLY cannot separate devices powered directly by the 125 VDC battery that are connected to the Mark* from devices which are also powered by the 125 VDC battery but NOT connected directly to the Mark*--again, contrary to false and popular belief. The Mark* just CANNOT distinguish between devices connected to the Mark* and devices not connected to the Mark*.

So, if the earth detection hardware jumper is IN in the <PD> core AND there is an earth detection card or function operating in the 125 VDC battery charger, the two are working"against" each other and they should not both be active or enabled simultaneously. And if they both are then detecting earths is going to be difficult and time-consuming. But, in reality neither will properly detecting an earth if both are enabled at the same time.

Again, if the same thing is happening to two or more units then it's very probable two (2) Mark VI turbine control panels have NOT failed in a similar manner and at nearly the same time. It's more likely that something similar or shared by the two Mark* turbine control panels is/are failing or failed. That could be ANY NUMBER of things, from earthing systems to temperature/humidity control (or lack thereof), or housekeeping (dust and dirt), to <DACA> power supplies, to dirty 125 VDC battery charger output(s), to failing/failed rack-mounted power supplies, to VPRO power supplies to earths. And, it could also be a combination of any (or all) of the above. Failure to adhere to industry standard earthing protection schemes and regularly testing and properly maintaining earthing systems can also contribute to or be the entire problem. Someone connecting a 440 VAC motor to the Functional earthing system, or connecting a field device to the Protective earth system. Or a shield drain wire to the Protective earth system--all of these could compromise the integrity of the independent earths. A change in the moisture content of the soil the earths are buried in, or a separation of earthing components in a particular system could also contribute to or be the problem.

Look for something similar to both machines or common to both machines as the root cause of the problem; that could ultimately lead to a failure of Mark* components or cards--but simply replacing the failed Mark VI card or component IS NOT resolving the root cause(s) of the problem and will only lead to more failures.

Again, please write back to let us know how the problem resolution is progressing!

Sear CSA
Thanks for your reply status of plant now we decided to switch of 125VDC from battery charger for each unit.
Each unit has separate 125VDC . and so far units stable and no trip. we will monitor the units and update you for any news.
can you please tell me the reasons make VCMI card reboot ?
Thanks and best regards

 

msalem73,

It's your machine and you have done what you want.

I don't understand why you are asking about what causes VCMI rebooting, BUT, I don't have any answers for you about that anyway.

Please do keep us informed on the status.

 

msalem73,

It's your machine and you have done what you want.

I don't understand why you are asking about what causes VCMI rebooting, BUT, I don't have any answers for you about that anyway.

Please do keep us informed on the status.

Dear CSA;
I asked this question because i saw from diag alarm history found this alarm on VCMI card .
i understood the card rebooting as see below and i dont know this card was rebooted due to over heating ,over current or what is the root cause of reboot.?

Mark VI DALMLOG Report 99 <Card reboot occurred here.>
100 <Card reboot occurred here.>
101 31-AUG-2021 19:00:39.7381 FC: 46 "IONET-2 Communications Failure"
102 31-AUG-2021 19:00:39.7645 FC: 50 "Using DEFAULT Input Data, Rack S0"
103 31-AUG-2021 19:00:46.2845 FC: 51 "Using DEFAULT Input Data, Rack T0"
104 31-AUG-2021 19:00:46.2984 FC: 47 "IONET-3 Communications Failure"

Thanks and best regards.

 

msalem73,

In my personal experience the reason for rebooting is the equivalent of power-cycling (removing and reapplying power; voltage dip; voltage spike; etc.).

In my personal experience, the <DACA>s are the worst offender when it comes to dealing with upsets in the power supply THEY receive. MANY inexpensive inverters are used for powering <DACA>s and if their output is not clean the <DACA>s can amplify any dips/spikes on their output which can cause nuisance and intermittent problems for the rack-mounted power supplies (on the right ends of the Mark VI processor racks).

However, the 125 VDC battery chargers have been known to "lose" filter capacitors over time and this causes their 125 VDC output to be dirty which can also cause problems for the rack-mounted power supplies.

Based on the information you have recently provided, at your site you have chosen to isolate (remove) the 125 VDC battery power supply to each Mark VI turbine control panel, and continue to run using the two <DACA>s. That's your choice, and since we don't understand how your turbine control panel power is supplied to the panel from the 125 VDC battery or the <DACA>s we can't make any further recommendations. Should this temporarily resolve the issues you have been experiencing, then it's a good presumption that there is something amiss with the 125 VDC system--either the battery charger output is dirty (dips; spikes; etc.) or there are serious 125 VDC battery ground issues, or there is some other problem we are unaware of (age/condition of battery cells; age/condition of battery charger(s); problems with other circuits supplied by the 125 VDC battery (Emergency compartment lighting; DC oil pumps; fire protection system (if powered by the 125 VDC battery; etc.)).

So, continue to monitor the problem and the Mark VI system(s). Use a storage oscilloscope to check the output of the 125 VDC battery charger for any problems. If the Mark VI "phantom" issues seem to have been resolved, then it's safe to presume the problem is with the battery or the battery charger output or some other 125 VDC circuit powered by the 125 VDC battery that also supplies power to the Mark VI.

If the "phantom" problems still persist, but perhaps at a lesser rate, then start checking the <DACA> power sources and outputs to the Mark IV.

Also, you can check the <CPF> power filter that is almost always provided with any Mark VI turbine control system for failed or failing components in any case. If you have reason to suspect there have been power supply spikes or dips in the past, it's probably not a bad idea to check the <CPF> components for signs of failure (burned or discolored components or connections; etc.). The primary purpose of the <CPF> is to prevent electronic noise produced by the Mark VI from getting out of the Mark VI and onto circuits powered by the Mark VI. It's really not the best input filter; it's more of a low- to mid-range "reverse" filter than anything. And, it's very often neglected and forgotten when performing periodic maintenance on the Mark VI turbine control panel.

Please write back to let us know how you fare in resolving this issue. Remember: Often, troubleshooting is a process of elimination (eliminating suspected problems by proving they ARE NOT the cause of the problem(s)). Therefore it should be methodical, it should be documented (including the process for testing as well as the results of the testing). And, eventually, you will arrive at the root cause(s). But, willy-nilly troubleshooting and trying several resolutions at once (often referred to the "shotgun approach to troubleshooting") IS NOT recommended. The root cause is never properly identified and different people will attribute the resolution to different solutions.

Best of luck! We cannot offer much more in the way of suggestions based on the information provided and we cannot see and know what you know (unless you tell us what you've seen and what you know)--and we know that English is probably not your first language which can make this difficult just by itself. Just try to stop and think: "What would I want to know about this situation if a complete stranger were asking me for help from afar?" That's EXACTLY what we need to know, too.