Gap conductors: GZTACSR and GTACSR

Lamifil Gap Conductors

Gap conductors consist of layers of trapezoidal shaped, temperature resistant aluminium zirconium wires around a high strength steel core. To allow the aluminium wires to move freely over the core the outer diameter of the core is smaller than the inner diameter of the innermost layer of AlZr wires. This “gap” becomes an essential part of the conductor and is giving the conductor its special characteristics.

GZTACSR  and GTACSR conductor advantages:

  • Increase line capacity
    GAP type conductors can carry up to twice the current of conventional overhead conductors due to their high temperature capability.
  • Easy replacement
    Gap conductors are an excellent solution for uprating overhead lines. Existing ACSR conductors can easily be replaced by Gap conductors offering up to double the capacity.
  • Reduction of thermal sag
    Excellent mechanical properties and substantial reduction of thermal sag under various load conditions allow to increase transmission capacity on existing lines at a  low cost and in a relatively short time.
  • Minimized tower modifications
    No or limited modifications to towers or structures are required.
  • Choice of alloys
    Several types of AlZr alloys can be used, each having different characteristics.
  • Reduce electro magnetic field level
    GAP conductor’s lower elongation coefficient may result in a reduction of the magnetic field under the line due to its maintaining greater clearance distance at the same current level.

Operating Temperature

Continuous Peak
GTACSR 150°C 180°C
GZTACSR 210°C 240°C

The innovative design involves:

  • Extra and Ultra High Strength steel core with adequately tested galvanisation and temperature resistance up to 250°C.
  • High temperature grease developed to allow the aluminium to move freely over the steel core while protecting the core from long term corrosion, resistant to temperatures up to 300°C.
  • Optimised in-house production of a wide range of aluminium zirconium alloys.
  • All layers consisting of trapezoidal wires, giving more conductive aluminium section.
  • Trapezoidal wires resulting in a fill factor of 98,5%.
  • Environmentally friendly surface finish for an emissivity higher than 0,6 right from day one.

Several manufacturers have developed a complete range of hardware for use with Gap conductors. These products are effective and easy to use. Lamifil can advise and offer line hardware for use with Gap conductors.

Lamifil Gap ConductorAfter a short training about the characteristics and installation of the conductor and the fittings, Gap conductors can easily be installed by experienced linesmen. If required, we can advise and offer specific installation tools for use with Gap conductors.

 

Read our GZTACSR case study

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