
FAQ
The key elements of an OHTL system include conductors, insulators, towers or poles, and various hardware and accessories. Conductors carry the electrical current, while insulators provide essential electrical isolation. Towers or poles support the conductors, and hardware and accessories (such as clamps, spacers, and dampers) ensure the system's structural integrity and safe operation.
Proper equipment selection is critical for ensuring the reliability, safety, and longevity of the entire power grid. Choosing high-quality, durable components and using the correct stringing and maintenance equipment, as provided by Ningbo Changshi, minimizes the risk of system failures, reduces maintenance costs, and ensures compliance with industry standards.
Common challenges in power cable installation include managing conductor sag and tension for overhead lines, and navigating complex, often urban, routes for underground cables. For OHTL stringing, improper tension can lead to sag issues, while for underground projects, friction and obstacles can damage cables during laying.
Our advanced tension stringing equipment for OHTL and comprehensive cable laying equipment for underground projects are specifically designed to address these challenges. Our products ensure precise tensioning, smooth conductor handling, and efficient cable pulling, preventing damage and significantly improving the speed and safety of installation projects.
Several key factors influence transmission efficiency:
-
Resistive Losses (I²R losses): The most significant source of loss is the resistance of the conductors. As current flows, it generates heat, and this energy is lost. The longer the transmission line and the higher the current, the greater the losses.
-
Conductor Material and Design: The choice of conductor material (e.g., aluminum, copper, or advanced composite conductors) and its cross-sectional area directly impacts its resistance. We provide a wide range of conductors and stringing equipment designed to minimize resistance and optimize performance.
-
Voltage Level: Transmitting power at a higher voltage dramatically reduces the current for the same amount of power, thereby decreasing resistive losses. This is why our equipment is designed to support high-voltage transmission lines.
-
Reactive Power: Unmanaged reactive power, which is necessary to maintain voltage but does no useful work, increases the total current flowing through the lines, leading to higher I²R losses.
-
Aging Infrastructure: Outdated equipment and aging conductors can increase resistance and contribute to inefficiency. Our advanced tools and equipment are essential for the modernization and maintenance of power grids.
Modernizing the power grid with our advanced equipment is key to boosting efficiency. We offer a comprehensive range of products, including:
-
Tension Stringing Equipment: Our precision-engineered tension stringing equipment ensures conductors are installed correctly with the optimal tension, reducing sag and preventing contact with obstacles, which can cause faults and losses.
-
Advanced Conductor Tools: We provide tools for working with advanced conductor materials, such as Aluminum Conductor Composite Core (ACCC), which are designed for high strength, low weight, and reduced sag. These conductors can carry more power with fewer losses.
-
Underground Cable Laying Equipment: For urban and sensitive environmental areas, our underground cable laying equipment facilitates efficient installation. Underground cables are less susceptible to environmental factors like weather and can be designed to minimize losses over shorter distances.
-
Tools for Reactive Power Management: Our specialized tools and accessories are used to install and maintain equipment like capacitors and reactors, which are vital for compensating for reactive power and improving the system's power factor.
By leveraging our state-of-the-art products, companies can build and maintain more efficient, reliable, and sustainable power transmission systems.
The journey of electricity is a four-stage process that forms the foundation of the modern electrical grid: generation, transmission, distribution, and consumption. It begins at a power plant, where electricity is produced. To minimize energy loss over long distances, transformers at the transmission substation "step up" the voltage to an extremely high level. This high-voltage electricity is then carried over vast distances by transmission lines, typically supported by tall towers.
Upon reaching a local area, the electricity arrives at a distribution substation, where another transformer "steps down" the voltage to a safer, more manageable level. From there, it is sent through distribution lines (the poles and wires you see in neighborhoods) and eventually to transformers on poles or pads near homes and businesses, where the voltage is lowered one last time for safe use.
As a manufacturer of specialized tools and equipment, Ningbo Changshi plays a critical role in every step of this process, from installing the high-voltage transmission lines to laying the underground cables that deliver power to our customers' doorsteps.
The primary difference between overhead and underground transmission lies in their physical placement and the equipment required.
-
Overhead Transmission: This method uses conductors suspended by tall towers or poles. It is the most common form of long-distance transmission because it is generally more affordable to install and easier to maintain. However, overhead lines are more susceptible to weather-related outages (e.g., storms, ice) and require a large right-of-way. Ningbo Changshi specializes in manufacturing the OHTL wire cable conductor tension stringing equipment and overhead tools and accessories necessary for this type of construction.
-
Underground Transmission: This method involves laying insulated cables within trenches, tunnels, or conduits. It is often used in urban areas or environmentally sensitive regions where aesthetics and space are a concern. Underground systems are more resilient to weather but are significantly more expensive to install and repair due to the specialized nature of the work. Our company provides a complete suite of underground cable laying equipment and tools to support these complex projects.

