Preformed helical anchor clamps for overhead lines

Preformed Spiral Anchor Clamps for Overhead Lines

Preformed spiral anchor clamps are mechanical fastening elements designed to secure, tension or anchor overhead-line conductors, cables or other compatible linear elements at a support point. The clamp consists of several metal wires preformed into a spiral shape, which are wrapped around the conductor during installation to create a stable mechanical fastening assembly.

This product group includes spiral anchor clamps with different lengths, wire diameters and numbers of spiral wires. The specific model must be selected according to the construction, outside diameter and mechanical load of the conductor or cable, as well as the installation conditions.

• Spiral wrapping – the preformed wires are wrapped around the conductor or cable.
• Mechanical grip – the spiral geometry creates contact between the clamp and the conductor surface.
• Load distribution – tensile force is transferred over a longer contact area.
• Anchoring – the loop or bend section of the clamp is connected to the appropriate support fitting or other line hardware.
• Maintaining conductor position – a correctly selected clamp helps keep the conductor in its intended position under tensile forces.

• Overhead power lines – for mechanical anchoring of conductors at supports.
• At line ends – where the conductor must be mechanically secured at an end support.
• At angle supports – when the construction and specific clamp model are suitable for such use.
• Tension assemblies – for transferring mechanical tensile force to the support hardware.
• Cable or strand fastening – if the specific clamp is technically compatible with the cable or strand used.
• Other overhead-line systems – according to the manufacturer's specified application and compatibility.

• Determine the conductor type – check the construction and material of the conductor or cable.
• Check the outside diameter – this is one of the most important clamp selection parameters.
• Evaluate the tensile load – the clamp must meet the mechanical requirements of the specific fastening assembly.
• Check the clamp length – it must correspond to the design of the specific model.
• Evaluate the fastening point – the loop must be compatible with the line hardware used.
• Check material compatibility – especially where conductors and fittings made of different metals are used.
• Follow the data for the specific model – mechanical load-bearing capacity and exact conductor range cannot be determined from appearance alone.

1. Check clamp and conductor compatibility. Make sure the selected model is intended for the specific conductor diameter and type.
2. Inspect the conductor. The installation area must be free from significant mechanical damage or deformation.
3. Inspect the clamp. The spiral wires must not be bent, stretched or otherwise deformed.
4. Mark the installation position. The clamp must be installed in the intended anchoring zone.
5. Start wrapping. Position the spiral wires according to their factory-formed shape.
6. Wrap evenly. The spiral wires must follow their natural helix and sit against the conductor.
7. Do not use excessive force. The spiral wires must not be stretched, straightened or twisted against their natural shape.
8. Check the loop area. It must be correctly connected to the intended fastening hardware.
9. Check all spiral wires. There must be no incorrectly bent or detached elements.
10. Check the complete assembly before loading. Mechanical load may only be applied to a correctly installed and inspected clamp.

• whether all spiral wires sit evenly against the conductor;
• whether there are any overlapping or incorrectly bent spiral wires;
• whether the clamp loop is correctly positioned in the fastening fitting;
• whether the conductor surface was damaged during installation;
• whether the clamp has shifted from its intended installation position;
• whether the complete support and line hardware assembly has been correctly installed.

• Selecting the clamp only by approximate conductor size.
• Considering conductor cross-section in mm² but not the actual outside diameter.
• Using the same clamp for conductors with different constructions.
• Failing to evaluate the mechanical tensile load.
• Straightening the spiral wires before installation.
• Stretching or forcibly twisting the spiral wires excessively.
• Using a deformed clamp or one damaged during transport.
• Installing only part of the spiral or leaving some wires improperly seated.
• Failing to evaluate compatibility between the loop and support hardware.
• Selecting a model only by wire diameter or number of spiral wires.

• ✅ Simple preformed construction.
• ✅ No complex bolted clamping mechanism required.
• ✅ Mechanical force is distributed over a longer section of the conductor.
• ✅ Variants are available for different conductor diameters.
• ✅ Models with different lengths and numbers of spiral wires are available.
• ✅ Convenient visual inspection of installation.
• ✅ Suitable for various mechanical fastening assemblies in overhead lines.
• ✅ When correctly selected, a compact anchoring assembly can be formed.

• ❌ The clamp is not universal for all conductor diameters.
• ❌ The conductor construction and actual outside diameter must be known accurately.
• ❌ Mechanical load-bearing capacity depends on the specific model.
• ❌ A deformed clamp cannot be considered equivalent to a new product.
• ❌ The spiral geometry must not be modified arbitrarily.
• ❌ An unsuitable model may not grip the conductor sufficiently.
• ❌ A model that is too small may damage or excessively compress the conductor.
• ❌ Nominal conductor cross-section alone is not sufficient for selecting the clamp.

Quick guide to selecting a spiral anchor clamp

Select a preformed spiral anchor clamp according to the specific overhead-line conductor or cable. It is important to check not only the nominal conductor size, but also its actual outside diameter, construction and required mechanical load-bearing capacity.