IEC 60865 lists equations for calculating short circuit forces inn flexible conductors.
I understand that in the case of reducing the number of spacers (i.e. increasing spacers span) conductors will be allowed to bend and hence the tension increases, till clashing occurs; however, this doesn't seem to be always correct for short spans like line dropper at substation entrance. Calculations show the pinch force decrease with increased spacing after a certain peak value, I can't understand this behavior.
I run the calculations, graph as attached, the conductor span is about 11 m. While it seems meaningless to have any difference with 6 or 7 m spacing as the actual number of spacers is just 1 for both ( 2 x 6 = 12 > 11 m).
any clue?
I understand that in the case of reducing the number of spacers (i.e. increasing spacers span) conductors will be allowed to bend and hence the tension increases, till clashing occurs; however, this doesn't seem to be always correct for short spans like line dropper at substation entrance. Calculations show the pinch force decrease with increased spacing after a certain peak value, I can't understand this behavior.
I run the calculations, graph as attached, the conductor span is about 11 m. While it seems meaningless to have any difference with 6 or 7 m spacing as the actual number of spacers is just 1 for both ( 2 x 6 = 12 > 11 m).
any clue?