Upgradin y'all

After 20+ years of great service from the systems in our
power plants, we are finally realizing there comes a time
when it would be better to replace/upgrade some of our systems
than to hope and pray we will find someone who can work on our stuff.
One piece of equipment that comes to mind is a temperature monitor.
Ours has 30 copper RTD inputs and the mfgr is no longer
making new ones nor are they supporting the one we have in service.
I have been leaning towards just getting a PLC to monitor the RTD's and alarm/trip on high temps.
Our operators/supervisors are used to having a "box" mounted on the panel of which you can just push a button and read the temperature.
It seems to me that you can just do the same thing with a PLC and some sort of view screen. But not everyone is convinced that making everything plc based is the best way to go.
With the ability of interfacing with just about any "thing" out there, How much is too much? I mean, it could get to the point to where the old and huge control panel get's thrown away and replaced with a view screen. Also, at what point do you start distributing your control functions rather than just putting all your eggs in one cpu?
Thanks in advance

Bob,

Having worked down South here in the Tennessee Valley Power Plants, I can say that there are some good reasons in a power plant to have separate control systems for different generator units. It is a very good example of why not to put all your controls in the same PLC.

I know of one TVA nuclear plant that did not melt down during a fire, because the controls were NOT all in a common box.

I mean, it could get to the point to where the old and huge control panel get's thrown away and replaced with a view screen.

Click to expand...

Yes, and this is what you should strive for to get the most benefits.
You should consider to have everything redundant, including hot backup of the main CPU.
Also, you should be considering to using distributed i/o in stead of wiring all signals back to a main control room via traditional cables and terminals.
This used to be a job for a DCS, but these days there are PLCs that can do this job just as well.
Expect this to be a major overhaul that will take time and cost money.
It is not a do-it-yourself job, but more a job for an integrator, probably allready with experience in power stations.

It is not uncommon to find those 10 ohm copper indicators replaced with paperless recorders - all the readouts on one screen, ethernet comm to the DCS, local trend screen if the operator selects it, local alarming or alarming via comm.

It's happened more than once.

Dan