ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
Top Posters(30 Days)
Potseal 11
Recent Posts
600 KW 120/208 3 Phase Y protection
by Yooperup. 07/21/17 09:27 AM
1913 American Electrician's Handbook
by gfretwell. 07/20/17 01:08 PM
Green House wiring
by ghost307. 07/20/17 09:10 AM
Permit Snafus...AHJs and Contractors Jump in
by HotLine1. 07/18/17 08:06 PM
New in the Gallery:
SE cable question
Popular Topics(Views)
239,193 Are you busy
174,588 Re: Forum
167,018 Need opinion
Who's Online Now
2 registered members (cableguy619, NORCAL), 39 guests, and 7 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate This Thread
Page 1 of 2 1 2
#128525 - 05/17/03 09:08 PM An Above Average Goof  
Bjarney  Offline
Moderator
Joined: Apr 2002
Posts: 2,527
West-Southern Inner-Northeast ...
  [Linked Image]

One finds electrical reports where a little slip-up evolved into a big problem.

In utility systems there are typically fat 125-volt battery sets {or sometimes 48 or 250V} that take care of transmission and distribution circuit-breaker tripping, so that AC can go away for whatever reason, and still be able to trip circuit breakers. [This is sorta' like AC-operated shunt-trip circuit breakers on building mains and exhaust fans discussed at E-C.net, but with DC-powered solenoids for dumping stored hydraulic pressure to part some big contacts.]

There are components that decide if breakers should be open or closed, that can get a bit complicated from a control-wiring point of view. Normally there are many thousands of feet of 14AWG wiring to interconnect all this stuff.

When this incident happened, it must have been absolutely mortifying to hear 15 high-voltage breakers opening at once. [They literally shake the ground in the process.] Very likely it took one slip of a screwdriver or a misapplied wire to initiate a seven-hour outage of 290,000 customers.

That would have spoiled my Tuesday. smirk smirk




[This message has been edited by Bjarney (edited 05-23-2003).]


Tools for Electricians:

#128526 - 05/18/03 05:11 AM Re: An Above Average Goof  
pauluk  Offline
Member
Joined: Aug 2001
Posts: 7,520
Norfolk, England
Er... Oops! Sorry about that folks.... [Linked Image]


#128527 - 05/18/03 08:18 AM Re: An Above Average Goof  
ThinkGood  Offline
Member
Joined: Aug 2002
Posts: 1,081
Milwaukee, WI
Hey, guys, watch this!!!!


#128528 - 05/19/03 09:44 AM Re: An Above Average Goof  
C-H  Offline
Member
Joined: Sep 2002
Posts: 1,497
Stockholm, Sweden
"Are you sure about this???"

"Course I'm sure. Just remove this wire here. We haven't got all day"


#128529 - 05/23/03 09:02 PM Re: An Above Average Goof  
amp-man  Offline
Member
Joined: Jun 2001
Posts: 141
Sacto, California US of A
Here's one about the phone company...

My Dad was a phone man, most of the time a central office guy in step, crossbar, or power. This was in a suburb of Los Angeles.

As some of you may remember, in the early 1960s everyone took the threat of a nuclear attack VERY seriously. Grade school kids did civil defense "duck and cover" drills once a month.

When civil defense air raid sirens throughout the region sounded for about two minutes at 10AM on the last Friday of the month, every school kid would crawl under their desk and curl up in the fetal position. After two minutes of warble tone, a steady siren tone yould signal the "all clear", and things would go back to normal. It was a regular reminder that a Russian (well, Soviet) H-bomb could be heading your way at any time. Cheery thought.

One day, early in the month, in the middle of the week, the sirens went off. There was mild panic; I mean, were we all going to go up in a mushroom cloud? And what difference would it make if you were curled up in a ball under your desk?

The "all clear" was sounded very quickly, and no one could figure out what the deal was.

That night at dinner, my Dad said that one of his fellow switchmen had been doing routine maintenance on some circuits right next to the civil defense siren circuits (which all went through the phone company central office). This guy bumped the CD equipment and triggered the sirens.

I don't recall that this fact was ever made public.

Of course, there was a telephone co. inquiry. My Dad said that on the morning that the poor schmuck was to be grilled by the investigative committee, the other central office guys were all giving him advice on how to play it, hopefully so he'd keep his job.

The winning advice was that he should dress up like a janitor, walk in with a fake mustache and carrying a broom and dust brush, and, in a fake German accent, say:

"Vell, I vas chust dusting zee equipment..."

And in the end, the guy kept his job.

Cliff


#128530 - 05/24/03 07:53 AM Re: An Above Average Goof  
pauluk  Offline
Member
Joined: Aug 2001
Posts: 7,520
Norfolk, England
Wonderful anecdote!

A lot of people never realized just how much went through telephone exchanges besides regular phone calls.

I don't know about employees of the Bell System (or GTE etc.), but anyone working for the old GPO (General Post Office) telephones in Britain had to sign the "Official Secrets Act."

This was basically a sworn statement that you would not reveal to any third party anything overheard or intercepted during the course of your work on the equipment, under penalty of being confined in the Tower of London (well not quite [Linked Image], but the penalties were five-digit fines and/or several years' possible jail time).

The central offices contained many leased lines of various types, for alarm control systems, private telex circuits between rather high-ranking officials, and so on.

When I was at an American TV station in 1995 we still had the old EBS system in place (I'm not sure, but I believe the system has now been replaced by something newer.) That two-tone signal that preceded the announcement was really quite dischordant and could almost have been designed to specifically give a feeling of impending doom! Fortunately, I never heard it followed by anything other than "This is a test of the emergency broadcast system..." [Linked Image]

By the way, talking of the civil defense angle, have you seen that the "Duck & Cover" film with Bert the Turtle is available on-line to view?




[This message has been edited by pauluk (edited 05-24-2003).]


#128531 - 06/01/03 11:08 PM Re: An Above Average Goof  
ThinkGood  Offline
Member
Joined: Aug 2002
Posts: 1,081
Milwaukee, WI
pauluk:

The EBS is now the EAS .

Here's an example of the old EBS tone.

Edit: I knew it was around the net somewhere. You'll need Quicktime to view this parody: http://www.montagar.com/~patj/atest.mov

[This message has been edited by ThinkGood (edited 06-01-2003).]


#128532 - 06/02/03 08:10 AM Re: An Above Average Goof  
C-H  Offline
Member
Joined: Sep 2002
Posts: 1,497
Stockholm, Sweden
I had never heard of the EBS/EAS. Interesting concept. You guys sure take things seriously.

(The only thing I know is that I'm supposed to turn on the radio in case the air raid sirens go off and it's not Monday 3 o'clock.)


#128533 - 06/02/03 10:15 PM Re: An Above Average Goof  
ThinkGood  Offline
Member
Joined: Aug 2002
Posts: 1,081
Milwaukee, WI
C-H:
Actually, the EBS was activated for weather emergencies more than anything else. The new EAS uses digital codes to limit activation to very specific areas, and to display the category of alert.

Bjarney:
The original post, for some reason, brings to mind Mr. Bean .


#128534 - 06/02/03 10:35 PM Re: An Above Average Goof  
Bjarney  Offline
Moderator
Joined: Apr 2002
Posts: 2,527
West-Southern Inner-Northeast ...
We've probably all had a few 'Mr. Bean' moments.


Page 1 of 2 1 2

Member Spotlight
Theelectrikid
Theelectrikid
Levittown, PA
Posts: 810
Joined: April 2004
Show All Member Profiles 
Featured:

2017 NEC and Related
2017 NEC
Now Available!

Shout Box
Powered by UBB.threads™ PHP Forum Software 7.6.0
Page Time: 0.019s Queries: 15 (0.003s) Memory: 0.8208 MB (Peak: 0.9962 MB) Zlib enabled. Server Time: 2017-07-22 04:42:01 UTC