Cross Arm for Poles and Towers
Function of the cross arm: The Angle iron fixed transversely at the top of a telegraph pole with a porcelain bottle, used to support overhead wires.
The cross arm is an important part of the pole tower, its function is used to install the insulator and the gold tools, to support the wire, lightning rod, and to keep a certain safe distance according to the regulations.
Cross arm classification
According to the use can be divided into: straight cross arm; Angle cross arm; Tensile cross arm.
According to the material can be divided into: iron cross arm; Porcelain cross arm; Synthetic insulated cross arm.
Usage method
Straight cross arm: only consider the vertical load and horizontal load of the wire under the normal condition without breaking the line;
Tensile cross arm: bear the vertical and horizontal load of wire, but also bear the tension difference of wire;
Angle cross arm: In addition to the vertical and horizontal load of the wire, it will also bear a large unilateral wire tension.
According to the stress situation of cross arm, single cross arm is used for straight bar or Angle bar below 15 degrees, while double cross arm is used for Angle bar, tensioning bar, terminal bar and branch bar with Angle above 15 degrees. (In some areas, double cross arm is adopted)
The cross arm is generally installed 300mm from the top of the rod. The straight cross arm should be installed on the receiving side, and the cross arm of the Angle rod, terminal rod and branch rod should be installed on the side of the cable.