He outer terminal for cable 138 kV It is a fundamental accessory for connecting high voltage cables with transformers, airlines, electrical substations and other transmission equipment. In systems of 138 kV, cable termination must provide stable electrical insulation, control the electric field and ensure safe operation under different environmental conditions.
The correct selection of a cable terminal 138 kV has a direct influence on the reliability of the entire installation. For this reason, Electrical transmission and distribution projects require accessories designed specifically for the voltage level, cable structure and installation conditions.
What is an external terminal for cable 138 kV?
And outer terminal for cable 138 kV is a device installed at the end of a high voltage cable to make a safe transition between the insulated cable and the electrical equipment or connecting line. Unlike an interior finish, The outer terminal is designed to work directly exposed to the environment.
An external termination of 138 kV may be subject to rain, humidity, pollution, solar radiation, temperature changes, wind and other environmental conditions. For this reason, The design must ensure adequate creepage distance and maintain good insulation properties throughout the life of the system.
In applications with XLPE cables, he outer terminal for XLPE cable 138 kV It normally incorporates elements intended to control electrical stress around the termination zone.. This control allows reducing the concentration of the electric field and improving the voltage distribution in the insulation..
Wire Terminal Applications 138 kV
He cable terminal 138 kV It is mainly used in high voltage installations where underground or transmission cables must be connected with different electrical equipment.
Among its main applications are:
- High voltage substations.
- Connection between underground cables and overhead lines.
- Connection of cables with power transformers.
- Connection with GIS and other electrical equipment.
- transmission networks 138 kV.
- Electric generation and transmission systems.
- High voltage industrial installations.
- Energy infrastructure projects.
in a substation, For example, he high voltage outer terminal 138 kV allows connecting the XLPE cable with electrical equipment while maintaining the insulation characteristics required by the system.
Design of an exterior termination of 138 kV
The design of a outer terminal for cable 138 kV must simultaneously consider the electrical characteristics, mechanical and environmental of the installation.
One of the most important elements is the electric field control system. When the semiconductor screen is removed from the cable during termination preparation, the distribution of the electric field changes considerably. The accessory must control this transition to avoid excessive concentrations of electrical stress.
The exterior of the terminal must also provide sufficient resistance against contamination and moisture.. For exterior applications, insulators can use materials such as porcelain or polymeric materials, depending on the design and project requirements.
The creepage distance and isolation distance should be selected considering the system voltage and environmental conditions.. In areas with high pollution, For example, it may be necessary to use a higher creepage distance.
External terminal for XLPE cable 138 kV
XLPE cables are widely used in modern high voltage networks due to their good electrical properties., thermal and mechanical. For this reason, he outer terminal for XLPE cable 138 kV constitutes one of the most used solutions for transmission installations.
During assembly, It is essential to respect the cable preparation dimensions. conductor diameter, XLPE insulation thickness, the metal screen, The outer shell and other parameters directly influence the selection of the accessory.
A properly designed terminal must fit the actual dimensions of the cable. For this reason, before making a cable termination 138 kV, It is usually necessary to confirm information such as:
- Conductor section and material.
- Driver diameter.
- Diameter over insulation.
- XLPE insulation thickness.
- Metal screen type.
- Cable outer diameter.
- Outer cover type.
- Cable preparation length.
- Rated current.
- Environmental conditions.
Electric field control
Control of the electric field is one of the essential functions of a high voltage terminal 138 kV.
At the end of the cable, The elimination of certain conductive layers modifies the distribution of the electric field. Without an adequate control system, concentrations of electrical stress may appear capable of reducing the useful life of the insulation.
Modern terminals use different field control technologies, depending on the manufacturer and design. The common objective is to achieve a uniform distribution of the electric field and avoid localized stresses..
The quality of the field control system is especially important in high voltage networks, where even small irregularities can have major consequences after long periods of operation.
Exterior insulator and environmental resistance
The external insulator constitutes another fundamental part of the outer terminal for cable 138 kV. Its function is to provide electrical insulation between energized parts and the grounded structure..
In outdoor installations, the insulator must withstand varying environmental conditions. Rain and moisture can form a conductive film on the surface. In industrial or coastal areas, Contamination can also affect insulation performance.
For this reason, Terminal design must consider creepage distance, the shape of the insulator skirts, resistance to contamination and the ability to withstand temperature changes.
Polymeric insulators offer advantages related to reduced weight, the ease of installation and certain characteristics of behavior against contamination. The final selection depends on the technical requirements of the project.
Testing for terminals 138 kV
Los accessories for high voltage cable must undergo different verifications before being used in transmission projects. The specific tests depend on the applicable standard, of fixture design and customer requirements.
For a outer terminal for cable 138 kV, can be considered evidence related to:
- insulation resistance.
- Withstand voltage test.
- Partial discharge measurement.
- Heating tests.
- impulse tests.
- Leakage check.
- mechanical tests.
- Environmental performance evaluation.
Partial discharge tests are especially important on high voltage accessories. A reduced level of partial discharge helps demonstrate that the isolation system and internal interfaces have been properly designed and manufactured.
Applicable standards
The manufacture and evaluation of a cable terminal 138 kV must be carried out considering the electrical standards corresponding to the project. For high voltage cable systems, International standards may establish requirements related to the cable, the accessories, electrical tests and operating conditions.
Among the standards that may be relevant is IEC 60840 for cable systems with extruded insulation and voltages higher than 30 kV up to certain high voltage levels. Depending on the project, There may also be additional requirements established by electrical companies, customer technical specifications or national standards.
For this reason, It is not advisable to select a outer terminal of 138 kV only according to the nominal voltage. The characteristics of the cable and all installation requirements must also be checked..
Selection of the outer terminal for cable 138 kV
To correctly select a external termination for cable 138 kV, several parameters need to be analyzed.
System voltage must be confirmed first. Afterwards, the conductor section and cable dimensions must be checked.. It is also necessary to know the type of metal screen and the configuration used for grounding..
Environmental conditions are also important. An installation in a coastal area may require different characteristics than an installation in an inland area with low pollution.
Besides, the customer should consider the short circuit current, operating temperature, the connection method, the mounting position and the available space in the substation.
Proper selection allows the cable terminal 138 kV work properly together with the cable and connected electrical equipment.
Instalation and maintenance
The installation of a outer terminal for XLPE cable 138 kV requires qualified personnel and appropriate tools. The preparation of the cable end must be carried out strictly following the dimensions indicated in the assembly instructions.
The insulation surface must be kept clean and free of particles., humidity and pollution. The interfaces between the different components must be installed correctly to avoid the appearance of defects during operation.
After installation, It is recommended to carry out the corresponding tests before energizing the system. Periodic inspections can also help identify potential contamination-related problems., mechanical damage or aging of exterior components.
Manufacturer of terminals and accessories for high voltage cables
Manufacturer quality is an important factor when purchasing cable accessories 138 kV. A professional supplier should be able to provide detailed technical information, installation dimensions, materials, electrical characteristics and test documentation.
Besides, for international projects, It is convenient that the manufacturer can offer customized solutions according to different types of cables and customer requirements.
He outer terminal for cable 138 kV can be manufactured for different conductor cross-sections and different cable structures. The final configuration should be determined based on the actual cable parameters and installation conditions.
Dosense Cable – Accessories manufacturer
Dosense Cable is a manufacturer of accessories for high voltage cables., offering solutions for terminations and accessories used in electrical transmission and distribution systems. As accessories manufacturer, Dosense Cable can develop and supply solutions according to cable specifications, the voltage level and technical requirements of the project.
For applications of outer terminal for cable 138 kV, Correct selection should be based on cable dimensions, the electrical system, environmental conditions and testing requirements. Our team can work with the customer's technical data to determine the proper fixture configuration.
Dosense Cable – Manufacturer of high voltage cable accessories and cable termination solutions 138 kV.