What they call this wire? Any Linemen here?

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I've noticed new and upgraded Grid transmission lines are using this twisted pair wire, instead of the traditional Aluminium-conductor steel-reinforced cable.

Looks like grey romex twisted, but it is on 138 kV lines predominantly, also seen it on some 69kV and 26 kV lines. What is it called and what are the benefits.
 
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There have been changes to transmission line designs. Perhaps the most significant change is use of composite materials, instead of steel, for the reinforcing. Not only do composites reduce weight, but thermal expansion is much less (less sag). The weight reduction allows use of different designs for the aluminum component of the line. Also, I'm not sure how prevalent at higher voltages, but it's possible to coat a conductor, too, which would alter its appearance.
 
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Originally Posted By: Vern_in_IL
I've noticed new and upgraded Grid transmission lines are using this twisted pair wire, instead of the traditional Aluminium-conductor steel-reinforced cable.

Looks like grey romex twisted, but it is on 138 kV lines predominantly, also seen it on some 69kV and 26 kV lines. What is it called and what are the benefits.


How are you getting close enough to see it? I've not heard of anything new.

Are you looking at the static?
 
You can clearly see the twist from ground level...

I believe it's called VR2 Cable... found this out about it:

Quote:

APPLICATIONS
VR2TM1 cable, a vibration-resistant, bare aluminum construction, is designed for use in overhead applications subject to Aeolian vibration and galloping due to wind and ice. VR2TM cable can bestrung to the maximum allowable tension limits without the need for additional vibration protection.

CONSTRUCTION
Southwire's VR2TM cable is composed of two identical bare conductors twisted together with a lefthand lay. This gives the cable a figure 8 spiral shape. This spiral shape disrupts the forces created by steady cross winds which cause cable vibration by presenting a continuously changing projected cable diameter to the wind.

This spiral shape, together with less torsional stiffness and varying bending stiffness also reduces or eliminates cable galloping due to combined ice and wind. VR2TM isengineered with a lay length that changes with conductor diameter. The engineered lay ensures that the product will install without bagging issues while still providing equal or better resistance to Aeolian vibration and ice galloping. The component conductors of VR2TM cable can be conductor types AAC, ACSR, AAC/TW, or ACSR/TW meeting the requirements of the appropriate ASTM standard. Other sizes available upon request.


http://www.southwire.com/products/VR2Cable.htm
 
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