Anchor clamps as a reliable and permanent connection

Anchor clamps as a reliable and permanent connection are used on low-voltage aerial bundled cables with or without neutral messenger and on telecommunications fiber-optic and coaxial cables. Their purpose is to tension the cable and, like an anchor or anchorage, fix the cable in one point with the possibility of a certain degree of cable deflection. Because of this way of functioning, they got the name anchor clamps. Sometimes, the term dead end clamps is also used. But considering that the term dead end clamps covers an even wider field of technical terms, I think that in our practice, that is, in the practice of manufacturers, linemen, supervisors, engineers and technicians who deal with low-voltage electrical and telecommunication insulated networks, the term anchor clamps is much better because it refers in the technical sense to a much narrower field of technical terms.

According to the type of cables on which they are used, anchor clamps are divided into:

Anchor clamps for cables with a neutral messenger (such as Marel anchor clamps type PA 1500, PA 1500i, PA 2000). The neutral messenger can be made of AlMgSi alloy or it can be an insulated ACSR conductor. The most common cross-sections are 54.6mm2, 70mm2, 71.5mm2, 35mm2, 50mm2.
Anchor clamps for self supporting cables (such as Marel anchor clamps type PA 25, PA 25-2, PA 435, PA 235, PA 80, PAC 80, PAA, PA). Most often, they cover the range of cable cross-sections from 16mm2 to 185mm2 and have up to 4 cores. It is allowed to tension cables with 4 or more cores.
Anchor clamps for telecommunications cables (such as Marel anchor clamps type DN 118, DN 318, DN 525, PA 1500 ADSS, PA 1500i ADSS, PA 48 ADSS). Most often, they they cover the range of cable diameters from 1 to 20 mm, the construction of the cable can be round, flat or figure-8.

Anchor Clamp Types
Anchor clamps can also be devided according to the method of tensioning the cables, and in this way we divide them into:

Anchor clamps with self-adjusting wedges. The way this type of anchor clamps works is such that the cable itself pulls the serrated wedges with its own weight, the wedges enter the body of the anchor clamp, and in this way apply pressure from both sides on the insulated jacket/sheath of the cable, thus gripping it. The more pressure or tension is applied to the cable, the anchor clamps grips it tighter.
Anchor clamps for telecommunications cables (such as Marel anchor clamps type DN 118, DN 318, DN 525, PA 1500 ADSS, PA 1500i ADSS, PA 48 ADSS). Most often, they they cover the range of cable diameters from 1 to 20 mm, the construction of the cable can be round, flat or figure-8.
Anchor clamps with one wedge. The way this type of anchor clamps works is such that the cable is placed inside the body of the clamp and locked with one serrated wedge. By applying pressure on the cable, i.e. by tensioning, the wedge enters deeper and deeper into the body of the anchor clamp and locks the cable.
Anchor clamps for telecommunicatisons cables (such as Marel anchor clamps type DN 118, DN 318, DN 525, PA 1500 ADSS, PA 1500i ADSS, PA 48 ADSS). Most often, they they cover the range of cable diameters from 1 to 20 mm, the construction of the cable can be round, flat or figure-8.
Anchor clamps with a bolt or bolts. The way this type of anchor clamps works is such that the pressure on the insulated sheath of the cable is achieved by using bolts that can be with or without a shear-off head with breaking torque.
Anchor clamps for telecommunications cables (such as Marel anchor clamps type DN 118, DN 318, DN 525, PA 1500 ADSS, PA 1500i ADSS, PA 48 ADSS). Most often, they they cover the range of cable diameters from 1 to 20 mm, the construction of the cable can be round, flat or figure-8.

Anchor clamps can also be devided according to the following three parameters:

Span from pole to pole, i.e. from anchor clamp to anchor clamp;
Diameter, i.e. cross-section of the cables;
Declared failing load of the clamp;

Other technical parameters, such as material selection, technical design, etc. most commonly depend on the place of installation of the clamps and the weather conditions in that place, as well as on specific technical requirements. The pressure made on the insulated sheath of the conductor when tensioning the clamp must never lead to its damage. The EN 50483 standard was adopted for the testing of anchor clamps and it defines the procedures and methods of testing. The most important ones are described below:

Tensile test at high temperature (SRPS EN 50483-3:2009; t. 8.1.2 / SRPS EN 50483-2:2009; t. 8.1.3), the purpose of this test is to ensure that the tension clamp does not slip excessively on the insulated neutral messenger during service and that any movement does not damage the insulation. It combines heat cycles with mechanical load.
Tensile test at low temperature (SRPS EN 50483-3:2009; t. 8.1.3 / SRPS EN 50483-2:2009; t. 8.1.4), the purpose of this test is to ensure that the tension clamp is suitable for use at -10 °C.
Gas atmosphere test – Combined test: (salt mist test - 5% (NaCl) and in humidity-saturated atmosphere in the presence of Sulphur dioxide. (SO2, 0,0667%) – Method 1 (SRPS EN 50483-3:2009; t. 8.1.4.3.1 / SRPS EN 50483-2:2009; t. 8.5.1.2.1) – Corrosion test, combined test shall consist of 4 cycles of 14 days. This 14-day cycle consists of 7 days in salt (atmosphere in coastal zones of seas and oceans) and 7 days in Sulphur dioxide (SO2 gas simulates very polluted atmosphere in industrial zones).
Climatic ageing test (SRPS EN 50483-3:2009; t. 8.1.4.4.1 / SRPS EN 50483-2:2009; t. 8.5.2.1), the test is conducted in six (6) weekly combined cycles of climatic restrictions: ultraviolet radiation, humidity, water spray and extreme temperatures (from -25 to + 70 ° C). Test conditions are designed to reproduce normal operating conditions. This test is carried out in a single test chamber for all conditions of climatic restrictions.