The piercing clamp for SIP is necessary to receive branching from the main trunk of a self-supporting insulated wire with copper or aluminum cables. Directly self-supporting wire is used to deliver electricity to the population, feeds street lighting lines. It is laid in the air way on reinforced concrete supports. It is characterized by power parameters from 0.4 kV to 35 kV. It can be a single-phase or three-phase wire with durable polyethylene insulation, which stably resists the sun's rays. Zero core in SIP is a carrier.
Device description
Branch piercing clamps for SIP are one of the most important elements in the transmission lines of electrical voltage, which has insulation. The safety of the conductivity of the electrical supply and the reliability of the entire air-insulated line directly depend on these clamps.
Contact in the clamps is constant and reliable during the entire life of the power line, which is more than 40 years. Also, an important safety factor is the tightness of the piercing clamps. Precipitation that penetrates the junction of wires and further under insulation causes irreversible negative processes that reduce the service life and expose the line to emergency situations. To prevent such consequences, the piercing clamps for SIP are tested under water with a voltage of up to 6 kV for a minute.
The inner part of the clamps at the contact points is filled with special grease that resists corrosion and, accordingly, prevents oxidative processes at the contact points of the clamp with the wire. Resistance to corrosion damage is tested in salt chambers in accordance with European standards and requirements.
Production material
In piercing clamps for SIP 2x16, copper alloy is used in the manufacture of contact teeth, followed by tinning of already made contacts. This technology makes it possible to reduce the cross section of the teeth, giving a decrease in force during the installation of the clamp. This affects the reduction of damage to the conductive core and insulating material.
Also, this development nullifies the possibility of galvanic processes at the junction with the aluminum wire of a self-supporting structure. The copper alloy covering the teeth has great strength, which provides the necessary piercing. This has a great effect at low atmospheric temperatures, when the hardness of the insulating element rises almost half of the standard values.
The stall head of piercing clamps for SIP is made of a special polymer, which is similar in temperature and mechanical parameters to the insulation of a self-supporting wire. With temperature fluctuations in the installation, the piercing strength of the SIP insulation also changes, which is necessary for safe and reliable contact under any atmospheric influences.
Reliable functioning of the piercing devices is possible at temperatures up to -50 ℃.
Design Features
The main body of the piercing clamp is made of metal or durable polymer plastic. In the manufacture of a polymer, the device is enveloped in fiberglass and the production material is a polyamide that is resistant to ultraviolet radiation. This contributes to the criteria of reliability, tightness and increase the life of the clamp.
Inside the piercing clamp device for SIP, there is a contact group in the form of pyramidal teeth that pass through the insulation and connect the clamp to the conductive elements of the line. The teeth are tinned and have a tenacious coupler with a flexible wire. Their configuration provides reliability in the connection.
In the upper part of the clamp are bolts for screed. As for the design features of the models, there can be two such elements. With certain manipulations, namely the scrolling of the lag bolt, the upper head breaks down. A clamp occurs and the contact is completed. It should be noted that after this operation, the piercing device after dismantling is no longer subject to operation.
Types of clamps
Many models have a removable insulated plug, which is designed to provide restoration of insulation on the branch piercing clip for SIP. Safe operation with the device is guaranteed by the lack of access to conductive elements. The clamp bolt is also isolated from the parts of the clamp that are in contact with voltage.
There are such types of piercing clamps:
- Small-sized branch clamp P 4. Designed and used for street lighting, the delivery of electrical energy to the consumer. Connects the main veins of 6-95 mm square. with wires having a cross section equal to 1.5 - 6 mm square.
- Branch clamp for dividing the line of wires for connecting the P 625 house. It has a design feature in the form of contact elements using tinned copper. It is used for branching into a house or street lighting. The main section is 6 - 150 mm square, the branch is 2.5 - 25 mm square.
- Piercing clamp for self-supporting insulated wire R 645. Connects trunk section 6 - 150 mm square. with a copper or aluminum branch section 4 - 35 mm square.
- The clamp P 70. The main line has 25 - 150 mm square. section, and branching - 25 - 120 mm square.
Technical features
Clips are intended for fastening only aluminum or copper insulated wires. The bolts are tightened with a 13 mm stall head. The head is made of aluminum, the device itself is implemented in open form to facilitate installation.
The clamp models P 70, P 150, P 240 have a protective cap with a removable design.
Terminals type P 617, P 619 and P 14 are designed with a separate fixation of wires for each line. They are used in places where branching of several highways is necessary. The main conductive line is fixed by gear fastening, and the branch line requires removal of insulating material.
Manufacturers and price
To date, the market for piercing clamps is dominated by several foreign manufacturers. Each of them produces devices with its own labeling, with its own modification of models (in general, similar to each other) and the price of a piercing clamp for self-supporting insulated wires is formed relative to the corporate pricing policy.
The leaders in the production of these devices are companies such as Ensto, Sicam, Niled, KBT and others.
Marking Options
As a rule, the marking of piercing clamps is different from each other. It depends on the manufacturing companies. In general, it contains information about the cross-section of wires, both the supply trunk and branch. The main determining parameters are the spectrum of the wire cross-section range.
If the number of branch elements is more than one, then the marking option will look like A x BB, in which A is the number of self-supporting insulating wires, and BB is their maximum cross section. For example, a piercing clamp for SIP 4x16 has 4 channels with a cross section of not more than 16 mm square.