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ACSR/TW is a concentrically
stranded conductor of varying layers, made with trapezoidal-shaped
1350-H19 wires over a high strength steel core. Each conductor
is patterned after existing "round strand" ACSR(ASTM
B-232), except that trapezoidal aluminum strands replace round
strands.
An ACSR/TWD design features
equivalent diameter, whereas ACSR/TW offers reduced diameter
with equivalent circular mil area.
The same diameter means an
increase in aluminum area of more than 20%. This means a
reduction in AC resistance in the order of 15%. The steel core
is increased proportionally to the aluminum in order that
existing stress-strain data used for sag and tension be
applicable to ACSR/TWD.
The ACSR/TWD design is
different from that of "round strand" ACSR in that
the trapezoidal layers are not self-supporting.
Intentional gaps between the
TW wires are a major part of the design. This allows gripping
devices, such as comealongs, to transfer the clamping load
through all layers to the core. The increased aluminum and
steel area means that larger compression fittings are required
than would normally be used on the "round strand"
ACSR of the same diameter. Conventional armor rods and
suspension shoes, which are diameter-sensitive, may be used.
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