ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
Shout Box
Recent Posts
334.80 and fire caulk
by gfretwell. 06/21/18 11:35 AM
Calling all Non-US members!! (Non-US only)
by HotLine1. 06/13/18 01:50 PM
GE Lighting Recalls LED Tube Lamps
by Admin. 06/12/18 09:32 PM
Ketra Recalls Recessed Downlights
by Admin. 06/12/18 09:17 PM
diazed fuses
by Texas_Ranger. 06/11/18 07:31 AM
New in the Gallery:
Plug terminals
Housebilding DIY wiring
Who's Online Now
0 registered members (), 21 guests, and 22 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
Page 1 of 2 1 2
4000A 480V Duct #124477
10/10/06 10:29 PM
10/10/06 10:29 PM
Admin  Offline
OP
Administrator
Member
Joined: Oct 2000
Posts: 3,498
NY, USA
Quote
If you have a 4000A pringle switch trip, make sure you take a look before you try to close it. Here is what I know...

480V 4000A AL Duct in a 14 story building in Arlington, VA. Pringle switch tripped and was reset and a fireball consumed a good portion of the 14th floor. Every 90 blew out (holes large enough to stick an arm much bigger than mine through) from the 14th to the sub-basement parking garage where the service is located. The true cause of this failure is known by few people, and I am not one of them. Just a reminder of the forces that we deal with. This happened over the 4th of July, so thankfully no one was injured. This could have been a lethal disaster. It wasn't....

VAElec
[Linked Image]

[Linked Image]

[Linked Image]

Tools for Electricians:
Re: 4000A 480V Duct #124478
10/11/06 01:29 AM
10/11/06 01:29 AM
A
Av-guy  Offline
Member
Joined: Dec 2004
Posts: 23
Bangkok,Thailand
What is a "Pringle switch"? BTW, How long did they take to restore power?

Re: 4000A 480V Duct #124479
10/11/06 06:58 AM
10/11/06 06:58 AM
R
RODALCO  Offline
Member
Joined: Dec 2005
Posts: 856
Titirangi, Akld, New Zealand
Amazing !!

LV faults near high capacity transformers 1 or 2 MVA or bigger have enormous amounts of power and destructive capacity as seen in these photo's.

Someone would have been very shaken and needed to change some un%$^s when closing that switch.


The product of rotation, excitation and flux produces electricty.
Re: 4000A 480V Duct #124480
10/11/06 08:54 AM
10/11/06 08:54 AM
G
ghost307  Offline
Member
Joined: May 2005
Posts: 943
Chicago Illinois USA
A "Pringle Switch" is a generic term used in reference to 100% rated Bolted Pressure Switches. The most common manufacturer used to the the Pringle Electric Co.

Here's the URL to a page that Eaton has about them. http://www.eatonelectrical.com/NASA...s&cid=1138850153208&Sec=products


Ghost307
Re: 4000A 480V Duct #124481
10/11/06 05:52 PM
10/11/06 05:52 PM
C
Celtic  Offline
Member
Joined: Feb 2005
Posts: 361
NJ
Wasn't it megged ?


~~ CELTIC ~~
...-= NJ =-...
Re: 4000A 480V Duct #124482
10/11/06 07:03 PM
10/11/06 07:03 PM
S
steve ancient apprentice  Offline
Member
Joined: Mar 2005
Posts: 169
west springfield,mass
Only one comment,
Glad no one got hurt and WOW

Re: 4000A 480V Duct #124483
10/11/06 09:37 PM
10/11/06 09:37 PM
M
mamills  Offline
Member
Joined: Nov 2001
Posts: 745
Wharton, Texas, USA
What did the pringle switch look like after this "event"? I know virtually nothing about this type of switchgear. Is PPE required for someone operating this equipment (or at least a real good idea)?

Mike (mamills)

[This message has been edited by mamills (edited 10-11-2006).]

Re: 4000A 480V Duct #124484
10/11/06 10:02 PM
10/11/06 10:02 PM
H
hypress  Offline
Member
Joined: Jul 2004
Posts: 129
Charleston WV
The plant has several Pingle switches.Most of them were installed mid 70s to late 80s. We have then on a RM program and we clean and lubricate the blades of the switches. We found that if you dont RM they may not open porperly. Ours are fused switches not electricaly operated . Pringles switches are bolted pressure contact switches and when the knives contact the stationary contacts they actualy have a cam on each knife that generates additional force to help ensure greater contact pressure.
To those who have not seen a Pringle switch they look like a custom made device not something mass produced a lot of pride goes into them.

Re: 4000A 480V Duct #124485
10/13/06 10:08 PM
10/13/06 10:08 PM
mxslick  Offline
Member
Joined: Oct 2004
Posts: 803
Atomic City, ID USA
VAelec:

What was the cause of this failure, or are you not at liberty to say?

"Violent" is too small a term for this one.....


Stupid should be painful.
Re: 4000A 480V Duct #124486
10/14/06 11:12 PM
10/14/06 11:12 PM
T
TwinCitySparky  Offline
Member
Joined: Mar 2006
Posts: 52
Minnesota
Quote
480V 4000A AL Duct in a 14 story building in Arlington, VA. Pringle switch tripped and was reset and a fireball consumed a good portion of the 14th floor.


I'd venture to say they had two major failures. I think the first more obvious than the second...

Page 1 of 2 1 2

Featured:

2017 Master Electrician Exam Preparation Combos
2017 NEC Electrician
Exam Prep Combos:
Master / Journeyman

 

Member Spotlight
electure
electure
Fullerton, CA USA
Posts: 4,268
Joined: December 2000
Show All Member Profiles 
Top Posters(30 Days)
twh 5
Popular Topics(Views)
247,710 Are you busy
185,019 Re: Forum
174,346 Need opinion
Powered by UBB.threads™ PHP Forum Software 7.6.1
(Release build 20180101)
Page Time: 0.023s Queries: 15 (0.004s) Memory: 1.0251 MB (Peak: 1.2000 MB) Zlib enabled. Server Time: 2018-06-25 00:02:52 UTC