Effect of conductor orientation on transmission line ampacity

  • Thread starter MrBuggy
  • Start date
  • #1
1
0
Hi guys,

I was playing around with conductor configurations and observed this phenomenon. Mind you these are for the High voltage transmission (138 kV) lines that span kms. So apparently, the orientation of the conductor relative to North will change the ampacity of the transmission line. Can anyone explain to me why this is the case? I mean it makes sense to me how the wind, elevation, latitude and etc. would affect ampacity as it tells us the sag, and how the sun hits the conductor.

Thanks,
MrBuggy
 

Attachments

Last edited:

Answers and Replies

  • #2
psparky
Gold Member
884
32
Hmmmm....good question. Here's a random, somewhat educated guess:

I know there some giant magnetic field in regards to the Earth. Also being parallel with the poles (north) as opposed to being perpendiclar to poles (East, West) must have some effect on the wire.

If there is some rotating magnetic field from the poles or somewhere else, that can increase or decrease current flow.
Now someone really smart can answer:)
 
  • #3
AlephZero
Science Advisor
Homework Helper
6,994
292
The line direction determines, in part, the amount of solar radiation received by a given conductor. It is used to
calculate the angle of incidence of solar radiation. EDSA provides two choices for line direction: north-south
and east-west. Line direction is normally a parameter of little interest. If you use a sun time of noon for your conductor evaluations, you will find that an assumed East-West orientation will yield a slightly more conservative result than an assumed North-South orientation. If you use an other sun time between 10 A.M. and 2 P.M., an
assumed East-West orientation will yield a slightly more conservative rating unless your latitude exceeds
roughly 55 degrees north, where an assumed North-South orientation becomes slightly more conservative.
Obviously, if you select ‘Night’ as your sun time, it makes no difference what you select for line direction.
http://www.poweranalytics.com/designbase/pdf/Bare_Wire_Sizing.pdf [Broken] page 12.

For example when the sun is due south, an E-W line "sees" more sunlight per unit length of line than a N-S line, unless the sun is directly overhead.
 
Last edited by a moderator:
  • #4
psparky
Gold Member
884
32
Or it could have absolutely nothing to do with the magnetic field and everything to do with the angle of the sun.
Missed it by that much......
 
  • #5
sophiecentaur
Science Advisor
Gold Member
2020 Award
25,386
4,959
At 1kW/sqm, there's a lot of power falling on a long line; makes you think. That's another thing I just learned on PF.
 

Related Threads on Effect of conductor orientation on transmission line ampacity

Replies
2
Views
823
Replies
9
Views
1K
Replies
14
Views
12K
Replies
12
Views
1K
  • Last Post
Replies
6
Views
6K
Replies
5
Views
6K
Replies
4
Views
888
Replies
10
Views
15K
Top