As per our study this 138kV, ACSR 795 MCM transmission line at the ambient conditions of(104 °F, 2ft/s, 45° wind angle) result in a conductor temperature of 172.2°F at a Max current of 689A and conductor is rated for a Max temperature of 212° F.
But as per ACSR conductor behavior, as temperature rises from 172.2°F, aluminum expands more rapidly than steel. Eventually, the aluminum tension will reduce to zero and then go into compression. Beyond this point, the steel carries the total conductor tension. These compressive stresses generally occur when conductors are operated above 176 °F to 200 °F. Greater sags than predicted at these elevated temperatures may be attributed to aluminum being in compression.
So when we want to rate this transmission line, what should be the maximum ampacity rating to consider? Considering the max ampacity of 689A will gives us a rating of 1.732 x 138kV x 689A = 165 MVA only.
I found the Ampacity ratings of ACSR conductor as below. What should be the temperature tolerance limit to consider, without significantly affecting the conductor life span?
But as per ACSR conductor behavior, as temperature rises from 172.2°F, aluminum expands more rapidly than steel. Eventually, the aluminum tension will reduce to zero and then go into compression. Beyond this point, the steel carries the total conductor tension. These compressive stresses generally occur when conductors are operated above 176 °F to 200 °F. Greater sags than predicted at these elevated temperatures may be attributed to aluminum being in compression.
So when we want to rate this transmission line, what should be the maximum ampacity rating to consider? Considering the max ampacity of 689A will gives us a rating of 1.732 x 138kV x 689A = 165 MVA only.
I found the Ampacity ratings of ACSR conductor as below. What should be the temperature tolerance limit to consider, without significantly affecting the conductor life span?