ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
ShoutChat
Recent Posts
Increasing demand factors in residential
by gfretwell - 03/28/24 12:43 AM
Portable generator question
by Steve Miller - 03/19/24 08:50 PM
Do we need grounding?
by NORCAL - 03/19/24 05:11 PM
240V only in a home and NEC?
by dsk - 03/19/24 06:33 AM
Cordless Tools: The Obvious Question
by renosteinke - 03/14/24 08:05 PM
New in the Gallery:
This is a new one
This is a new one
by timmp, September 24
Few pics I found
Few pics I found
by timmp, August 15
Who's Online Now
0 members (), 260 guests, and 20 robots.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
Page 2 of 2 1 2
#36714 04/15/04 06:33 PM
Joined: Feb 2002
Posts: 375
G
Member
I think the loss was $1 million per day.

#36715 04/15/04 07:36 PM
Joined: Mar 2001
Posts: 333
S
Member
Bellagio is back in business. I think I heard it cost them $12.5 million? I wonder if the slot's pay-outs will be tightened up for awhile?

steve


Steve
#36716 04/15/04 07:57 PM
Joined: Mar 2004
Posts: 391
B
Member
Wow. So, essentially these folks just paid $12,500,000 to make sure that their primary and secondary power supplies run in different duct banks?

That's "quality" with a capital "6"! [Linked Image]

-John

#36717 04/15/04 08:41 PM
Joined: Mar 2001
Posts: 333
S
Member
I don't know if they corrected the "engineering" or just pulled new cables to restore power.


This just in - http://www.reviewjournal.com/lvrj_home/2004/Apr-15-Thu-2004/news/23660454.html


steve


[This message has been edited by stamcon (edited 04-15-2004).]


Steve
#36718 04/16/04 01:33 AM
Joined: Feb 2004
Posts: 1,438
Member
Quote
He said there are no plans to redesign or re-engineer the generators, electrical systems or cable conduits until the investigation is complete

I'm actually pretty curious about this one... Not your typical "bird across the phases" thing.... Which is actually what messed up LAX a few days ago... [Linked Image]

-Randy

#36719 04/28/04 08:53 PM
Joined: Apr 2002
Posts: 2,527
B
Moderator

#36720 04/28/04 09:40 PM
Joined: Aug 2001
Posts: 599
N
Member
Bjarney,
Your link just takes me to the home page. I did see the post I think you are referencing earlier today. I don't quite understand the authors description of t tapping multiple generators to the primary side. [Linked Image]
I haven't been able to post there for some reason lately so I am waiting to see more of that thread.

#36721 04/28/04 11:19 PM
Joined: Apr 2002
Posts: 2,527
B
Moderator
Ooops. Try cut and pasting thread238-93479 in the search field.

[Hopeffully the pop-ups won't drive you mad.]

#36722 12/01/04 10:07 PM
Joined: Aug 2001
Posts: 599
N
Member
I ran across this thread and thought I would post some updated info on this subject. (From a source close to the issue)
As I now understand it the normal and emergency feeders were not installed in the same "duct." They were however, installed through the same man holes.
A bit of clarification is in order here. The "emergency" feeders were in fact an optional standby system making the mixing of systems NEC compliant. The true emergency system for the hotel worked just fine.
The initial problem resulted from a faulted cable.
More clarification! The cables were not racked in the manholes. They were laying on top of each other and the stress at a pinch point (probably where the cable enters or exits the duct) damaged the cable. Also, there was an engineering decision to rely the cable shields as the equipment grounding conductors. The end result of which contributed to the the overheating and failure of the cable.
The faulted cable was on the bottom taking out many of the cables above it when it failed. This is why the optional standby system didn't work. The transfer switches are smart enough not to transfer into a fault. The cables that were active had to be de-energized to work on the system.
A couple of thing can be learned here.
1.Always rack and fireproof medium voltage cables in man holes.
2.Always run a table 250.122 sized equipment grounding conductor with medium voltage circuits. (Shields are not rated to Carry ground faults for more than a few cycles. After which over heating and cable damage will surely occur.)
3.Spend the money to do partial discharge testing once a year. This small investment would have caught this problem before it happened.

One sad side note: I never saw this in the news but heard it from industry sources.
After the hotel was up and running again an electrician from (I believe) the original installing contractor and a rep from the transfer switch manufacturer were looking at an issue in the medium voltage gear. The electrician reach inside to point something out when the voltage tracked down his arm and flashed over. The electrician Died of his injuries a few days later and the transfer switch rep was severely burned. The transfer switch rep was doing start up on one of our jobs when this happened but I haven't hared an update on him in a while. I will post back to this thread when I found out.

Disclaimer: All info is second hand from people closely involved in the re-work. I believe everything I have stated to be accurate.

#36723 12/02/04 02:05 PM
Joined: Apr 2002
Posts: 2,527
B
Moderator
Thanks for the update and comments, Nick.

Sad to hear of the loss. It only takes a moment of lost concentration.

Page 2 of 2 1 2

Link Copied to Clipboard
Powered by UBB.threads™ PHP Forum Software 7.7.5