ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
Shout Box
Recent Posts
Inspections and Testing
by Texas_Ranger. 04/24/18 07:09 AM
FEMA height and electrical equiment.,
by HotLine1. 04/20/18 08:49 AM
This anti-theist is priceless!!!
by LongRunner. 04/19/18 04:02 PM
Recall notice: Square D Services Switches
by gfretwell. 04/18/18 01:24 PM
Big Square D service switch Recall
by sparkyinak. 04/18/18 12:30 AM
New in the Gallery:
Housebilding DIY wiring
SE cable question
Who's Online Now
1 registered members (Texas_Ranger), 6 guests, and 11 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
Sodium cables #182850
12/13/08 10:27 PM
12/13/08 10:27 PM
A
Albert  Offline OP
Member
Joined: Aug 2006
Posts: 76
Falls Church, VA
One of the oddest electrical technologies of the past is the sodium cable. As the name indicates, it's an insulated power cable with metallic sodium as a conductor, in place of the usual copper or aluminum. Apparently it was "the next big thing" for a while in the 1960s, but as far as I know, it never caught on - though it probably "caught fire" a few times!

On pages 24-26 of this presentation, there's information about sodium cables and a cutaway photo of
one:
http://www.ewh.ieee.org/soc/pes/icc/subcommittees/subcom_e/E4/2005/8Hans.pdf

The entire presentation is quite interesting; check out the "Blues Brothers" on page 19.

Alber

Work Gear for Electricians and the Trades
Re: Sodium cables [Re: Albert] #182852
12/13/08 11:03 PM
12/13/08 11:03 PM
N
NJwirenut  Offline
Member
Joined: Sep 2001
Posts: 806
Bergen County, NJ
Interesting stuff!

How would you make a reliable electrical connection to a sodium conductor? Sodium is so soft that it makes the "cold flow" problems of aluminum look like nothing. I can't see how any kind of crimp or mechanical lug is going to stay tight.

Then there's the whole "reacts explosively with water" thing...

Re: Sodium cables [Re: NJwirenut] #182853
12/14/08 12:02 AM
12/14/08 12:02 AM
A
Albert  Offline OP
Member
Joined: Aug 2006
Posts: 76
Falls Church, VA
Yes, terminations must have been a major problem. The only thing I've seen in that regard is a reference to threaded connectors; I suppose they used some kind of lug that was screwed onto the exposed conductor. But it must have been difficult to come up with a design that could be screwed on tightly enough to make a good connection while not breaking the conductor.

It's really incredible that such a technology could actually have been approved and deployed by utilities. Apparently its only advantage was cost savings; surprisingly (to me) sodium was cheaper than copper and aluminum.

When I first heard of sodium cables, I thought they would be used for some exotic super-duper extra-high-voltage cryogenic superconducting transmission system, but in fact the application was ordinary secondary-voltage underground residential distribution.

When I brought up the topic on another list, a former lineman said one of the problems was that when water got into the cable due to jacket damage, the conductor would corrode for a long distance from the point of entry. His crew ended up replacing a lot of the stuff.


Featured:

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

 

Member Spotlight
Attic Rat
Attic Rat
Bergen Co.,N.J. USA
Posts: 524
Joined: December 2003
Show All Member Profiles 
Top Posters(30 Days)
Popular Topics(Views)
245,909 Are you busy
182,965 Re: Forum
172,778 Need opinion
Powered by UBB.threads™ PHP Forum Software 7.6.1
(Release build 20180101)
Page Time: 0.020s Queries: 15 (0.004s) Memory: 0.9517 MB (Peak: 1.0755 MB) Zlib enabled. Server Time: 2018-04-24 12:17:20 UTC