Transmission Line Strain Clamp and the Meaning of Its Model
Release time: 2025-07-14
Currently, there are many types of transmission line strain clamps, with different functions. However, commonly used ones include NLL aluminum alloy transmission line strain clamps, copper-aluminum equipment clamps (brazing), NXJ overhead insulated wedge clamps, etc. Tension clamps for transmission lines are used to fix the conductors to withstand the tension of the conductors. Installation requires the construction personnel to first bring the device to the designated position, and then install it with tools. NLL Aluminum Alloy Transmission Line Strain Clamp The NLL series bolt-type aluminum alloy transmission line strain clamps are suitable for 10kV and below overhead lines. They are used to fix aluminum stranded wires or steel core aluminum stranded wires on strain poles. They are used in conjunction with overhead insulated aluminum conductors and insulation covers for insulation protection. The NLL aluminum alloy tension clamp has good performance after 1008 hours of artificial weather aging test, demonstrating its weather resistance. It has constant clamping force, a direct current resistance ratio between 0.85 and 0.9, and a large contact surface between the clamp and the conductor. Its overload capacity reaches more than twice the rated current, and it always operates below a DC resistance ratio of 1, with excellent thermal cycling performance. There is no electromagnetic loss, and it is corrosion and oxidation resistant since it is made of high-strength special aluminum alloy. The casing is made of anti-oxidation high-strength aluminum alloy casting, with no energy loss. The power frequency withstand voltage is ≥18KV, ensuring no breakdown for 1 minute. The cable insulation layer does not need to be removed for the wedge structure to be directly installed, making installation simple and reliable. The installation involves connecting the pull rod to the connecting fittings, connecting the fittings to the insulator, keeping the main body opening facing downward as much as possible, and pulling the wire to the suitable position with a tensioner. Place the insulated conductor in the inner cavity of the main body, then insert the insulated wedge core, ensuring both wedge cores are level. Tap the insulated wedge core to ensure it is level after installation, then remove the tensioner and adjust the nut until the tension meets engineering requirements. Ensure that the tension clamp tightens the conductor without pulling out the core. It is recommended to reserve a conductor length of at least 1 meter on the jumper side of the wedge core tail end. Suitable for distribution lines of 10kV and below, fixing overhead insulated aluminum conductors or bare aluminum conductors on angle or terminal poles' insulators, thereby securing or tightening the overhead conductors. Used in conjunction with insulation covers for insulation protection. Generally used for steel core aluminum stranded wires, hydraulic type, with steel anchors typically forged and welded. Mainly used to fix conductors to withstand conductor tension and to hang conductors on strain insulator strings or pole towers. The clamp body is made of high-strength aluminum steel material. It has a smooth appearance and long service life. Installation and use are simple and convenient. NLD--1, 2, 3... indicates the model. The meaning of the model is: N - Tension clamp for transmission lines; L - Bolt type; D - Inverted type: for example, NLD-1 indicates a type 1 bolt inverted tension clamp for transmission lines. Represented by the letters NY. N - tension clamp for transmission lines, Y - compression type " - " followed by numbers as nominal cross-section. Represented by the letters NB. N - tension clamp for transmission lines, B - explosive pressure type " - " followed by numbers as nominal cross-section.
