Hi all,

Need help about a decision :

On one Compression station the respopnsable decide to change the Control system Speedtronic Mark 5 by a newely Speedtronic Mark 6. Why ? I do not know.

I want to know if any one can help me and explain me if really it is necessary to do this retrofit. This compression station was started on june 1995. I search the economics and techicals reasons to do as this renovation.

Is Mark 5 obsolete over the world?

Our MARK 5 is TMR and the HMI is IDOS.

Thanks for your help.

 

DAMENE Amar,

GE have issued an end-of-product life letter for the Mark V. Some people get very nervous when they read those letters, and salespeople use them to their advantage.

There are lots of Mark I, Mark II, and Mark IV turbine control systems still out there in the world, running units with little or no problems. Proper maintenance, familiarity and a good source of spare parts are all that's required.

I would suspect that if this unit is driving a compressor, the decision to convert to a Mark VI might be to integrate the compressor- and compressor auxiliary controls into the Mark VI, something which cannot easily be done with Mark V.

The cost of upgrading an <I> (with IDOS) to a GE Mark V HMI using a GE-provided solution can be very high, but there are alternatives available in the marketplace which can ease the budgetary pain.

We really don't know all the factors involved in the decision which was made. As you have written to control.com before about aero-derivative units (LM units), it may be that another factor was that the Mark VI can more easily accommodate some of the aero auxiliaries and I/O than the Mark V.

So, it's likely there were a lot of factors driving the decision that you may or may not be aware of. Some people just never really developed a good feeling for the Mark V (lots and lots of Diagnostic Alarms; many difficult and cryptic troubleshooting tools requiring knowledge of command line operating systems conventions; the <I>s were multi-tasking, but could only have one application running on the display at a time; and so on).

It just may be that the site personnel were unhappy with the control system and its operator interface and its capabilities, and wanted something different and felt that they were getting something newer and more user-friendly (that would be a subjective evaluation, not an objective evaluation), and something that could be more easily integrated with the rest of the plant systems and auxiliaries.

I'm also surprised to hear you say they have purchased a Mark VI; the Mark VI is being pushed aside in favor of the Mark VIe. If the compression station is set on replacing the Mark V and you're trying to get the compression station to change it's mind, you might be more successful with getting them to choose a Mark VIe.

But, it's likely there were multiple factors involved in the decision, and while the Mark V is a very good control system and has many years of life ahead of it, a new control system probably has some very good advantages. Remember: There are no new ARCnet cards available for <I>, and that could be a major driving factor in the decision, and should be considered even if they don't upgrade the entire control system.

 

Previous discussed issues for control system upgrade, refer to thread below.

Docendo Discumus

http://www.control.com/thread/1026250322#1224646123

 

I worked in the GE Optimization & Control Business over a year ago and was present for the developement of the Mark Ve, a 7 day replacement for the Mark V. I recommend you go with the Mark Ve. It uses the existing panel and the Ve system is extremely powerful and will be around for a long time.

The best part is that the outage is short and basically the system comes tested from the factory in a same size wooden crate as the existing panel. About 2-3 days to install. Don't be afraid. You can not go wrong.

 

I would argue strongly (and have in past posts) that the only reason to upgrade to a Mark Ve is the short outage time. If some functionality (case temperature management or wide wobbe control, etc.) is required immediately for a base load plant, then go for the Mark Ve.

But, after you upgrade to a Mark Ve, the panel still has a *lot* of Mark V cards in it: TCQCs, TCEAs, TCEB, TCTx, TCDAs, TCRAs. And what is the upgrade plan for these cards? I don't think it's really defined yet; so, one is left with a control system that has some Mark VIe-compatible cards, and a lot of Mark V cards. (And there's that (not so) little matter of the Mark V end-of-life letter.)

One has to wonder how much it's going to cost to replace the remaining Mark V cards with something newer if and when they become available. The outage duration will again likely be short, but the cost?

The Mark Ve is not really a long-term solution. It's more of a short-term solution and should be considered as such.