Electricity is transmitted at very high voltages to reduce energy loss during long-distance transport. The power loss in a transmission line is calculated by the formula Ploss=I2R, where I is the current and R is the resistance of the line.

By increasing the voltage (V), the current (I) can be significantly reduced to transmit the same amount of power (P=VI). Since the power loss is proportional to the square of the current, even a small reduction in current leads to a dramatic decrease in wasted energy, which is mostly lost as heat. This makes high-voltage transmission highly efficient for moving large amounts of power over vast distances.

Alternating Current (AC) transmission is the most common method used worldwide. AC systems are easily converted to different voltage levels using transformers, making them versatile for the power grid. They are used for both short and long distances.

Direct Current (DC) transmission, also known as HVDC (High-Voltage Direct Current), is becoming increasingly popular for very long-distance transmission. DC systems are more efficient over long distances and require fewer conductors than AC systems. However, converting voltage levels in DC systems is more complex, making them less practical for local distribution networks.

Working with overhead transmission lines involves specific safety precautions due to the high voltages. Key concerns include:

• Flashover: Electricity can "jump" across a gap from a live line to an object or person, even without direct contact. This phenomenon is known as a flashover and can be fatal.

• Environmental Factors: Adverse weather conditions like high winds, ice, and snow can cause physical damage to the lines or support structures.

• Equipment Failure: The high-voltage equipment, including insulators, switches, and transformers, must be meticulously maintained to prevent catastrophic failures.

• Maintenance: Safe maintenance procedures, such as live line/bare hand work and lockout/tagout, are critical to protect workers.

Our equipment and tools are designed to meet or exceed international safety standards, ensuring reliability and worker protection during construction and maintenance.

The use of bird guards and deterrents is critical for maintaining the reliability and safety of power systems. Birds, especially large raptors, often perch and nest on transmission towers. This activity can lead to several problems:

• Electrocution: A bird can complete an electrical circuit by simultaneously touching two energized conductors or an energized conductor and a grounded part of the tower. This not only results in bird mortality but also causes power outages and potential damage to equipment.

• "Streamer" Faults: Bird droppings (streamers) are highly conductive and can bridge the gap between energized and grounded parts, causing flashovers and short circuits. This is a common cause of unexpected power failures.

• Nesting Material: Birds building nests on insulators or other critical components can introduce foreign conductive materials that compromise the integrity of the electrical system, leading to faults and fires.

By installing high-quality, purpose-built bird guards and deterrents, we ensure the safety of wildlife while simultaneously protecting the power grid from costly outages and maintenance issues.

Ningbo Changshi specializes in manufacturing a comprehensive range of equipment designed to mitigate bird-related risks. Our product line includes:

• Insulation Covers and Sleeves: These are designed to cover and insulate exposed conductors and equipment, preventing birds from making direct contact and completing a circuit.

• Perch Guards and Spikes: Strategically installed on tower cross-arms and other perching surfaces, these devices make it difficult or impossible for birds to land, discouraging them from nesting or roosting in hazardous locations.

• Bird Diverters: Placed on overhead ground wires, these are visual markers that increase the visibility of the lines, helping to prevent mid-flight collisions, especially for migratory birds and in areas with low visibility.

All our products are made from durable, high-quality insulating materials that are resistant to UV degradation and harsh environmental conditions, ensuring a long service life and reliable protection.

Our avian protection equipment is a cost-effective solution for preventing power system failures. The initial investment in high-quality bird guards leads to significant long-term savings by:

• Reducing Maintenance Costs: Fewer power outages and equipment faults mean less need for emergency repairs, thereby lowering operational and maintenance expenses.

• Extending Equipment Lifespan: Preventing flashovers and electrical surges caused by bird activity protects expensive components like transformers and insulators from damage, extending their operational life.

• Improving Grid Reliability: By minimizing the risk of unplanned outages, our solutions help power companies deliver a more consistent and reliable service to their customers.

At Ningbo Changshi, we understand the challenges faced by power companies and are committed to providing innovative, reliable solutions that support the sustainable and efficient operation of power infrastructure worldwide.

Installing bundle conductors requires specialized equipment to handle the multiple conductors simultaneously and maintain proper spacing. At Ningbo Changshi, we provide a complete suite of tools for this task, including:

• Hydraulic Pullers and Tensioners: These are crucial for the controlled and precise stringing of multiple conductors under a constant, preset tension. We offer models designed specifically for 2, 3, or 4 bundle conductors.

• Conductor Stringing Blocks (Sheaves): Our multi-groove stringing blocks are designed to accommodate the individual sub-conductors of a bundle, ensuring they are strung in the correct configuration without damage.

• Anti-Twisting Braided Steel Ropes: Used as a pilot wire to pull the conductors, these ropes are engineered to prevent twisting, which is a common problem when stringing multiple lines.

• Bundle Conductor Spacers: These essential devices are installed at regular intervals along the span to maintain the precise separation between the sub-conductors and prevent them from clashing due to wind or other factors.

Our equipment is designed to ensure a safe, efficient, and reliable installation process for even the most complex bundle conductor projects.

Bird diverters are designed to increase the visibility of power lines, which birds often fail to see, especially in low light conditions or bad weather. They work by using a combination of visual cues:

• High Visibility: They are typically made in bright, contrasting colors (like yellow, orange, or white) that stand out against the sky and ground.

• Reflectivity: Many diverters incorporate reflective strips or materials that catch sunlight and moonlight, making them highly noticeable at all times.

• Movement: Certain types of diverters are designed to rotate, spin, or flutter in the wind, creating a dynamic visual that captures a bird's attention and prompts it to change its flight path.

By making the conductors more conspicuous, bird diverters provide birds with enough warning to avoid a collision, thus protecting both the wildlife and the reliability of the power grid.

The market offers several types of bird diverters, each designed for specific applications and environmental conditions. Common types include:

• Spiral or Helical Diverters: These are rigid, corkscrew-shaped devices made of PVC that are wrapped around the conductor. They are lightweight and easy to install.

• Swinging or Flapper Diverters: These typically feature a reflective or brightly colored body with a clamp that attaches to the line, allowing the body to swing and flutter in the wind.

• Marking Spheres: Larger, spherical markers are often used on shield wires or in areas with high migratory bird traffic to provide a highly visible object that is easily seen from a distance.

Our bird diverters are designed for easy and safe installation, often using a hot stick, which allows crews to install them on energized lines from the ground or a bucket truck, minimizing downtime and ensuring worker safety.

Proper installation is crucial for the long-term reliability of a connector. At Ningbo Changshi, our equipment is designed to ensure a precise installation every time. For compression connectors, this process involves:

1. Preparation: The conductor is cleaned to ensure optimal electrical contact.

2. Positioning: The connector is placed onto the conductor at the designated splice or termination point.

3. Compression: Using a hydraulic compression tool and the correct die set, the connector is compressed onto the conductor, creating a permanent bond. We supply the full range of tension stringing equipment, including the high-quality hydraulic crimping tools and accessories required for these tasks.

Proper installation is crucial for the long-term reliability of a connector. At Ningbo Changshi, our equipment is designed to ensure a precise installation every time. For compression connectors, this process involves:

1. Preparation: The conductor is cleaned to ensure optimal electrical contact.

2. Positioning: The connector is placed onto the conductor at the designated splice or termination point.

3. Compression: Using a hydraulic compression tool and the correct die set, the connector is compressed onto the conductor, creating a permanent bond. We supply the full range of tension stringing equipment, including the high-quality hydraulic crimping tools and accessories required for these tasks.

Connector failure is a major cause of power outages and can be attributed to several factors:

• Improper Installation: This is the most frequent cause, often resulting from using the wrong size tool, die, or applying incorrect compression force. This leads to a weak electrical and mechanical connection.

• Environmental Stress: Extreme weather, such as wind and ice loads, can cause mechanical stress, while atmospheric pollution and salt spray can lead to corrosion over time.

• Conductor Overheating: A poor connection can have high electrical resistance, causing localized heat buildup, which can weaken the connector and the conductor itself, leading to a thermal runaway and eventual failure.

To ensure connectors perform reliably for their full lifespan, we recommend the following best practices:

• Use the Right Equipment: Always use certified, high-quality connectors and the corresponding hydraulic crimping tools and dies as specified by the manufacturer.

• Proper Training: Ensure all technicians are fully trained in the correct installation procedures.

• Regular Inspections: Implement a program of regular inspections, using tools like thermal imaging cameras, to detect early signs of overheating at connection points.

• Preventative Maintenance: Address any signs of corrosion or damage immediately to prevent catastrophic failure. Our range of maintenance tools and accessories are designed to assist with all aspects of this work.

Specialized vehicles are essential for the safe and efficient construction and maintenance of overhead transmission lines. The primary types include:

• Bucket Trucks: These are the most common utility vehicles, equipped with an insulated bucket at the end of a hydraulic boom, allowing linemen to safely work on live power lines at height.

• All-Terrain Tracked Vehicles: For projects in rugged or remote areas with soft ground, snow, or steep slopes, tracked vehicles (like those from PowerBully or UTV International) are used to transport equipment and personnel to the job site.

• Tension Stringing Equipment Trucks: For large-scale projects, these trucks are an integral part of the tension stringing process, carrying and controlling the specialized winches and pullers needed to precisely install conductors. As a leading manufacturer of OHTL stringing equipment, our products are used on and with these specialized vehicles.

If a power line falls on your vehicle, your top priority is safety.

• Stay inside your vehicle! The vehicle acts as a protective cage (a "Faraday cage"), and the ground around the car may be energized.

• Warn others to stay away. Honk your horn and roll down a window to shout to any bystanders to keep a safe distance of at least 10 meters (33 feet).

• Call for help. Immediately call emergency services and the local utility company.

• Only exit in an absolute emergency. If the vehicle is on fire, you must jump clear of the vehicle, landing with your feet together, and shuffle away without lifting your feet. This is a crucial safety technique to avoid becoming a path for electricity.

How does Ningbo Changshi's equipment relate to these specialized vehicles?

Cleaning a live or "hot" power line is a specialized task that requires precise equipment and demineralized water. The most common methods are:

• Truck-Mounted Hot Line Washing: A dedicated truck with a demineralized water tank, high-pressure pump, and a hydraulically-actuated boom is used to spray the insulators.

• Helicopter Insulator Washing: For remote or hard-to-access areas, a helicopter equipped with a belly-mounted water tank and a non-conductive washing boom provides a fast and efficient solution.