PGA 10-300mm² 34-133mm Energy-saving Type Parallel Trench Wire Clamps for Overhead Cables
The parallel groove clamp is the most widely used power connection connector at present, the purpose is to connect two power transmission lines, so that the power transmission can continue. The power fitting is a weak link in the transmission and distribution line, and has high requirements for resistance. If the resistance is too large, the heating phenomenon during the operation of the line will obviously lead to the burning and fusing of the line, which will cause large-scale power outages and cause serious damage. Economic losses.
The parallel groove clamp is used for the connection of small and medium section aluminum stranded wire or steel core aluminum stranded wire and the steel stranded wire of the overhead lightning arrester at the position that does not bear the tension, and also used for the jumper connection of non-linear towers. Power engineering materials (fittings) are mainly used for connecting wires to connect to each other in power line engineering.
PGA series torque energy-saving parallel groove clamp is a brand-new non-load-bearing connection fittings, which are mainly used in power transmission, substation, and distribution line systems, and play the role of wire connection and jumper connection. The special alloy with high strength, high conductivity and intermediate electrode potential is processed by special process, and has good mechanical and electrical properties.
Product features and Installation matters
1. Light weight (weight ratio of the crimping sleeve to the weight of the grooved wire clamp = 1:8.836)
2. Less specifications, easy to carry, reduce labor intensity of construction personnel
3. Less construction time and convenient live work
4. Construction quality assurance (hydraulic clamp)
5. No need to apply anti-oxidant protective oil
1. The degree of contamination of the contact surface when installing the parallel groove wire clip has a certain influence on the contact resistance. Before installing the wire clip, ensure that the wire groove is clean.
2. In the contact form of the parallel groove wire clip, the larger the contact area, the lower the contact resistance. When designing the wire clip, try to use surface contact and increase the contact area.
3. When the parallel groove clamp is installed, the greater the contact pressure, the smaller the contact resistance. Choose standard parts with well-processed and uniform coating, and apply conductive grease during installation, which can effectively improve the contact performance of the parallel groove clamp and reduce the contact resistance.
From the characteristics of metal materials, we know that under the condition of stress, the wire will inevitably produce a certain amount of creep, which is more serious in the parallel groove clamp with high local pressure, which makes the wire slightly thinner and the diameter decreases. Without a proper compensation function, the grip of the grooved wire clip on the wire will decrease, resulting in stress relaxation. When the material is determined, the creep of the wire is related to time, pressure, tension and ambient temperature. The greater the pressure or tension on the wire and the higher the ambient temperature, the more serious the creep of the wire, and the change curve is exponential and increases with time. growing and increasing.
In order to maintain the stability of the holding force of the parallel groove clamp on the wire, during construction and installation, there must be enough external force to generate a suitable pressure on the wire to prevent the parallel groove clamp and the wire from loosening or relative slippage; After the external force disappears, the parallel groove clamp should be able to provide a relatively constant pressure on the wire to compensate for the creep effect of the wire caused by changes in current, temperature, wind speed, corrosion, etc.
When the bolt-type parallel groove clamp is installed, the torque applied to the bolt or nut often varies from person to person, and generally no special measuring instrument is used to check the torque, resulting in different bolts of the same clamp or between clamps installed by different personnel. The resulting stress on the wire is inconsistent. If the pressure is too large, the wire will creep too much; if the pressure is too small, the clamp and the wire will lack sufficient pressure and gripping force in the early stage of operation. The quality of the spring washer also seriously affects the mechanical stability of the clip. If a poor spring washer is selected, the plastic deformation of the spring washer will be large after being subjected to external force, which will cause the installed wire clip to not obtain the proper pressure compensation when the wire creeps.
The H-type parallel groove wire clamp is installed with special hydraulic tools, and the pressure on the wire is relatively uniform and constant. The connection with the wire is a one-time hydraulic setting, so that the inner wall material of the wire clip is embedded in the outer layer of the wire. Because the wire clip and the outer strand of the wire are the same aluminum-based material, it can reduce stress relaxation and compensate for wire creep.
The best mechanical stability should belong to the wedge-type parallel groove clamp. Due to the use of the bow-shaped structure and the wedge block, when the wire creeps due to various reasons, the bow-shaped structure and the wedge block can compensate for the creep, and the initial pressure during installation is provided by the special bullet, which can be achieved by reasonable control of the dose. goal of controlling stress