posted on Sep, 13 2005 @ 12:15 PM
I haven't seen the news this morning, but from what I saw last night, there were three different scenario's.
(Keep in mind the utilities don't like outages and will spend considerable monies to prevent them.)
One which looked like a small - usually 120 volt - protective relay wire was cut or disconnected.
The second sounded like they were changing over to a computer controlled operating/dispatching set up and there was an error in either the connections
or the software.
I doubt this was a problem since most computerized control cutovers are done a bit at a time testing as they go.
The last indicated a new line or rebuilt transmission line was connected incorrectly.
You'll note there are three conductors on AC transmission lines.
They're labeled A-B-C. (A phase, B phase, C phase.)
You'll also note there are transpositions between conductor locations in the field at a tower or pole.
Has to do with harmonics and inductive problems.
That means a line can be arranged A-B-C leaving a station and it should be A-B-C at the receiving station.
If a tranposition in the field or at the station is not done correctly you'll have an incoming line arranged A-C-B for example.
At the end of the job, field personnel will drive or fly the line making note of which conductors are which as they go.
Then, if they are sure the conductors are arranged correctly they make a formal statement saying so.
Depending on the line's voltage, there are switch panel instruments the operator/dispatcher can turn on and compare the incoming line with the
station busses etc.
Higher voltage lines are done much the same way, but you can't use the switch panel instruments to make comparisons.
In this case, technicians read secondary voltages at the relays in the station.
When everybody has checked their end of the job and are sure things are correct, only then is the switch closed at the receiving station paralleling
the new or rebuilt line with other lines and station equipment.
If . . . there's a total screw-up - and I find it hard to believe there would be - and conductors are mis-arranged, closing the switch at the
receiving station makes for a major close-in fault (short circuit).
In over thirty years of operating major power stations I never saw a line that was mis-arranged at either end.
Human error type stuff happens now and then, but compared to the amount of operations that are accomplished the figure is very, very small.
If an employee does make an error, there's always an investigation.
First, second and third tier of supervision if the operating end of things are what's involved.
If there's a safety issue involved, the people involved in the investigation go quite a bit further up the ladder.
If the employee involved has a good track record, he gets a letter in his file.
If he has a bad track record, there's a good chance he'll be working in a different not-so-hands-on job elsewhere in the company.
Most times at a lesser rate of pay.
I don't think any of the above scenarios are what caused the problem.
Part of it can be how a particular media reporter translates what the company spokesman says and also that the company spokesman may not fully
understand what happened or doesn't have the full and complete story.
Every once in a while, a newpaper reporter would come to the power station where I worked, get a tour, get the basics explained to him/her and write
the story so far out of line that it was hard to believe.
Every one is an expert in one field or the other.
I'm sure most of you have had your occupation or industry written about and most times the media understanding of things is virtually nil.
All of which makes me wonder about the other things they write about.
Not so much in terms of liberal or conservative leanings, but actually understanding what the heck is going on when they write about a particular