A 33 kV overhead line is a medium-voltage electrical line used to transmit power from larger substations to local distribution points. Its components are specifically designed to handle this voltage and the greater mechanical loads that come with it. Key components include:

• Line Supports: These are often robust steel poles or concrete poles (like PSC poles) that are stronger and taller than those used for lower-voltage lines. This provides the necessary ground clearance and stability for the heavier conductors.

• Conductors: The wires themselves are typically made of ACSR (Aluminum Conductor Steel Reinforced), which provides a high strength-to-weight ratio. These conductors have a larger cross-section than those on 11 kV lines to handle higher current and reduce power loss over longer distances.

• Insulators: To prevent current from arcing to the support structures, a series of pin-type, post-type, or suspension disc insulators are used. For 33 kV lines, a greater number of insulator discs or a more robust design is required compared to 11 kV lines.

• Line Hardware: A variety of fittings, clamps, and cross-arms are necessary to securely hold the conductors and insulators to the poles. These accessories are larger and stronger to withstand the increased tension of a 33 kV line.

The installation of a 33 kV line demands specialized, heavy-duty equipment to ensure a safe and efficient project. Ningbo Changshi provides a comprehensive range of equipment tailored for these requirements:

• Tension Stringing Equipment: For pulling the thicker, heavier conductors, our hydraulic puller and tensioner machines are essential. They provide the precise, controlled force needed to string the conductor without damage, maintaining the correct sag and tension across long spans.

• Conductor Rollers and Stringing Blocks: These are specially designed with larger grooves and robust frames to support the heavier conductors and guide them smoothly over the poles and cross-arms during the stringing process.

• Earthing and Grounding Kits: Safety is our top priority. We supply high-quality, reliable earthing kits that are crucial for de-energizing the line and protecting workers from residual voltage and accidental power surges.

• Climbing and Safety Tools: We provide a wide selection of insulated tools, harnesses, and specialized climbing equipment that are vital for linemen working at height on 33 kV structures.

By using our equipment, contractors can execute 33 kV projects with confidence, knowing they have the right tools for the job.

While both are considered medium-voltage lines, there are several key differences that affect their design, components, and purpose.

• Purpose: 11 kV lines are typically used for local distribution, bringing power from a local substation directly to transformers in residential or commercial areas. 33 kV lines, on the other hand, are used for longer-distance sub-transmission, connecting one substation to another or supplying power to large industrial areas.

• Physical Size and Components: Due to the higher voltage and increased power load, a 33 kV line requires larger conductors, stronger poles, and more robust insulators. The physical size of the components is a direct reflection of the greater mechanical and electrical demands.

• Installation Equipment: The installation of a 33 kV line often requires more powerful equipment. For instance, the puller and tensioner machines used for 33 kV projects have a higher pulling capacity to handle the larger conductors and longer spans.

• Safety Requirements: The minimum safe working distances are greater for a 33 kV line than for an 11 kV line, requiring stricter safety protocols and more extensive use of specialized insulated tools.

Understanding these differences is key to selecting the correct equipment for your project, a decision that can significantly impact both safety and cost-effectiveness.

An 110 kV overhead line is a high-voltage system used for regional power transmission. Its design and components are engineered to handle the greater electrical stress and mechanical loads compared to lower-voltage distribution lines. Key components include:

• Towers (Supporting Structures): These are typically steel lattice towers or concrete poles, which are significantly taller and more robust than those used for distribution lines. They are designed to withstand high winds, ice accumulation, and the heavy weight and tension of the conductors.

• Conductors: These are typically ACSR (Aluminum Conductor Steel Reinforced), chosen for its excellent strength-to-weight ratio. For 110 kV lines, a single conductor per phase is common, but in some cases, bundled conductors (two wires per phase) are used to increase current capacity and reduce electrical losses.

• Insulators: Insulators are essential for isolating the energized conductors from the grounded tower. For 110 kV, a suspension insulator string made of multiple porcelain or glass discs, or a single composite insulator, is used. The number of discs is determined by the voltage, environmental pollution, and climate.

• Ground Wires: A single ground wire (or shield wire) is often installed at the top of the tower to protect the phase conductors from lightning strikes. An OPGW (Optical Ground Wire) is a common type, which also contains fiber optic cables for grid communication.

The construction of a 110 kV line is a large-scale project that demands specialized, heavy-duty equipment. Ningbo Changshi specializes in manufacturing and supplying this exact machinery. Key equipment includes:

• Hydraulic Pullers and Tensioners: These are the core of the conductor stringing operation. Our hydraulic puller and tensioner machines provide the precise, controlled force needed to string the conductors without damage. For larger, longer projects, high-capacity models are essential.

• Heavy-Duty Stringing Blocks: Our stringing blocks are designed with larger grooves and robust frames to support the greater weight and diameter of 110 kV conductors. These are crucial for protecting the valuable conductors from damage during installation.

• Anti-Twist Steel Wire Ropes: Due to the long spans and heavy loads, high-strength and anti-twist ropes are necessary to guide the conductors smoothly and safely.

• Tower Erection Tools: For the steel lattice towers, specialized gin poles, winches, and rigging equipment are used to lift and assemble tower sections safely and efficiently.

Our complete range of Overhead Transmission Line Equipment is engineered to meet the stringent demands of 110 kV construction, ensuring a safe and efficient stringing process.

Safety is the paramount concern on any high-voltage project. Working on 110 kV lines requires strict adherence to safety protocols and the use of specialized tools to protect crews.

• Minimum Approach Distances: The electrical field around a 110 kV line can arc over a considerable distance. Workers must maintain a safe minimum approach distance at all times, typically around 4 meters or more, depending on local regulations.

• De-energization and Grounding: Before any work begins, the line must be completely de-energized, tested for voltage, and securely grounded using high-voltage earthing and grounding equipment to prevent accidental re-energization and dissipate any stored charge.

• Use of Insulated Equipment: When work on or near live lines is necessary, it must be performed using specialized insulated tools and hot sticks that are rated for the specific voltage.

• Personal Protective Equipment (PPE): Linemen must wear a full suite of PPE, including insulated gloves, safety helmets, and fall protection harnesses, at all times while working at heights.

We at Ningbo Changshi are committed to worker safety. Our high-quality, durable Overhead Tools and Accessories are manufactured to international standards, providing the confidence that they will perform reliably when it matters most.

A low voltage overhead line discharge rod is a critical safety tool used by electricians and linemen to safely remove any residual electrical charge from a power line or equipment after it has been de-energized. Even after a line is switched off, it can retain a static or capacitive charge, which can be dangerous and cause an electrical shock.

The primary purpose of a discharge rod is to provide a safe, controlled path for this stored energy to flow to the ground. This process ensures that the line is completely free of any electrical charge, making it safe for workers to begin their maintenance or construction tasks. Our discharge rods are made with high-quality insulating materials to protect the user from any potential electrical hazards.

Using a discharge rod correctly is vital for safety. The procedure should always follow strict protocols:

1. Wear Appropriate PPE: Always ensure you are wearing the correct personal protective equipment (PPE), including insulated gloves, safety glasses, and a hard hat.

2. Verify De-energization: Before using the discharge rod, the line must be confirmed as de-energized using a voltage detector.

3. Connect to Ground: Connect the grounding end of the discharge rod to a reliable ground source first. This establishes the safe path for the charge.

4. Discharge the Line: Holding the insulated handle of the rod, slowly and carefully bring the hook or tip into contact with the conductor or equipment to be discharged. You may hear a small spark as the residual charge dissipates.

5. Confirm Discharge: Once the charge is gone, it is good practice to leave the discharge rod connected to the line for a short period to ensure a complete discharge.

Our discharge rods are designed with ergonomic, insulated handles and robust grounding clamps to make this critical safety procedure as straightforward and reliable as possible.

While both tools involve connecting a system to the ground for safety, their functions are distinct:

• Discharge Rod: The main function is to temporarily remove residual or static charges from a de-energized line or equipment. It is used as a final safety check before work begins.

• Earthing (Grounding) Rod: This is a part of a permanent grounding system. An earthing rod is a long metal rod driven into the earth to provide a continuous, low-resistance path for fault currents to flow into the ground, protecting the system from lightning strikes and short circuits.

Our product range includes both specialized discharge rods for temporary safety procedures and a wide variety of earthing accessories for permanent grounding systems, giving our customers a complete solution for their safety needs.

A low voltage overhead line typically carries a voltage of less than 1,000 volts, often 400V/230V in many countries. Its primary purpose is to distribute power from local transformers to individual consumers, such as homes and small businesses. Unlike high-voltage lines that transmit power over long distances, low-voltage lines are the final link in the electrical network. Their relatively low voltage and short spans make them distinct from larger transmission lines, yet they are crucial for a reliable power supply.

The most common modern method for low voltage overhead line installation uses Aerial Bundled Cables (ABC). This system combines insulated phase conductors, a neutral conductor (often the support wire), and sometimes a street light conductor, all twisted together into a single bundle. Key components and installation methods include:

• Self-Supporting Conductors: The bundled design means the neutral wire acts as a messenger cable, supporting the entire weight of the bundle, which simplifies installation.

• Insulated Wires: The insulation on each wire significantly reduces the risk of electrical faults from contact with trees or other objects.

• Specialized Accessories: Installation requires specific accessories like tension clamps, suspension clamps, and insulated piercing connectors, all of which must be installed correctly to ensure safety and prevent power loss.

We provide a full range of Overhead Tools and Accessories specifically designed for the safe and efficient installation of ABC cables, ensuring a secure and reliable connection for every consumer.

Even though they are "low voltage," these lines still carry dangerous levels of electricity and require strict safety protocols and specialized tools.

• Insulated Hand Tools: Linemen must use insulated tools (e.g., pliers, wrenches) and wear insulated gloves to protect against accidental contact with live wires.

• Temporary Support Equipment: During maintenance or installation, temporary supports and cable rollers are used to manage the weight and tension of the ABC cables, preventing damage and ensuring a safe working environment.

• Earthing and Grounding: For any de-energized work, portable earthing kits are essential to prevent accidental re-energization and to discharge any residual static charge.

• Specialized Connectors: Insulated piercing connectors are a key tool for creating a secure, waterproof, and safe connection to the main line without having to strip the cable, which is faster and reduces the risk of short circuits.

At Ningbo Changshi, we provide a complete selection of these Overhead Tools and Accessories, empowering linemen to perform their jobs safely and efficiently, whether they are installing new lines or repairing existing ones.

The conductor is the most critical material in any overhead line, as it's what carries the electrical current. There are several common types, chosen based on factors like voltage, distance, mechanical strength, and cost.

• All Aluminum Conductor (AAC): Made of pure aluminum, AAC is lightweight and has good conductivity, making it ideal for short spans in urban areas.

• All Aluminum Alloy Conductor (AAAC): This conductor is stronger and more corrosion-resistant than AAC, making it suitable for medium-length spans and coastal or industrial environments.

• Aluminum Conductor Steel Reinforced (ACSR): The most common type for high-voltage transmission. It features a strong steel core surrounded by aluminum strands. This combination provides excellent mechanical strength for long spans while the aluminum provides good conductivity.

• Aerial Bundled Cable (ABC): Used for low-voltage distribution, ABC consists of multiple insulated conductors twisted together. This design improves safety and reduces the risk of electrical faults.

Our hydraulic pullers and tensioners, as well as our specialized stringing blocks, are designed to handle all these conductor types, ensuring a smooth and damage-free installation process.

Insulators are essential components that prevent electricity from flowing from the energized conductors into the grounded support structures. The quality of the insulator is paramount for safety and system reliability. The main types of materials are:

• Porcelain: A traditional material known for its high dielectric strength, durability, and resistance to environmental factors.

• Glass: Similar in performance to porcelain, glass insulators are popular because a broken disc is easy to spot from the ground.

• Composite/Polymer: A modern alternative, these insulators are lightweight, have high mechanical strength, and excellent resistance to pollution and vandalism.

We provide a variety of Overhead Tools and Accessories and insulated tools that are specifically designed for the safe handling and installation of these insulators, protecting both the equipment and the linemen.

o ensure the reliability of the power grid, maintenance is a continuous process that can be categorized into three main types:

• Preventive Maintenance: This involves regular, proactive inspections and repairs to prevent future failures. It includes activities like thermal imaging to detect hot spots, visual inspections for sagging conductors or damaged insulators, and vegetation management to prevent tree contact. Our tools for these tasks, such as specialized telescopic hot sticks with measuring capabilities, are essential for safety and efficiency.

• Corrective Maintenance: This is the reactive repair of components after a fault or outage has occurred. For example, replacing a conductor that has snapped due to a storm or replacing a shattered insulator. This type of maintenance often requires a rapid response and relies on our heavy-duty stringing equipment and a comprehensive range of overhead tools to restore service quickly and safely.

• Predictive Maintenance: This advanced method uses technology, such as drones and smart sensors, to monitor the real-time condition of components and predict when a failure is likely to occur. This allows crews to perform maintenance exactly when it is needed, minimizing unnecessary work and preventing outages.

The choice of supporting structure depends on the line's voltage, the conductor's weight, and the terrain. The most common types are:

• Wooden Poles: The most common for low-voltage distribution lines due to their low cost and ease of installation.

• Concrete Poles: Very durable and long-lasting, often used for medium-voltage lines.

• Steel Poles/Lattice Towers: Used for high-voltage transmission lines, these are robust structures designed to support heavy conductors over long spans.

No matter the material, our comprehensive suite of equipment is crucial for every stage of work. We provide everything from specialized stringing equipment for pulling and tensioning conductors to smaller, essential overhead tools for assembling components and ensuring the entire system is built to last. Our solutions support projects from the initial pole setting to the final conductor stringing, making us a true one-stop supply partner.

Performing maintenance on overhead lines requires a specific set of reliable, high-quality tools to ensure safety and efficiency. Our extensive product line is designed to meet these needs:

• Insulated Tools and Hot Sticks: For any work on or near live lines, these are non-negotiable. Our hot sticks and other insulated tools allow workers to perform tasks from a safe distance, preventing electric shock.

• Portable Earthing and Grounding Kits: Before any de-energized work can begin, the line must be properly grounded to prevent accidental re-energization. We provide a range of earthing and grounding kits for all voltage levels.

• Conductor and Guy Wire Tools: Maintenance often involves adjusting conductor tension, repairing splices, or securing guy wires. We supply specialized ratcheting wrenches, tension meters, and crimping tools to ensure these connections are strong and secure.

• Climbing and Safety Equipment: Safety is our top priority. Our range includes durable climbing irons, harnesses, lanyards, and other personal protective equipment (PPE) to protect linemen working at height.

Overhead lines are exposed to a range of environmental and mechanical stresses that can lead to common problems, all of which our maintenance equipment helps address:

• Conductor Sagging and Vibration: Over time, conductors can stretch and sag, reducing their clearance from the ground. This can be caused by heat, heavy loads, or fatigue from wind-induced vibration. Maintenance involves re-tensioning the lines and, in some cases, installing vibration dampers to prevent future damage.

• Insulator Contamination and Failure: Dust, salt, and pollution can accumulate on insulators, compromising their insulating properties and leading to flashovers. Maintenance may involve cleaning or replacing damaged insulators, a task made safer with our insulated tools.

• Hardware and Structure Degradation: Corrosion, rust, and physical damage from storms can weaken poles, cross-arms, and line hardware. Routine inspections and using our reliable, rust-resistant tools are critical for identifying and fixing these issues before they cause a catastrophic failure.

There are three critical measurements that are essential for the safe and reliable operation of any overhead line:

• Sag: This is the vertical distance between the highest point of a conductor and its lowest point in a span. Proper sag ensures the conductor has enough slack to handle temperature changes, wind, and ice loads without becoming too taut. Inaccurate sag can lead to conductor failure or insufficient clearance.

• Tension: This is the mechanical force exerted on the conductor. It's directly related to sag and must be within the conductor's design limits. Excess tension can cause stress on the conductor and supporting structures, leading to a system failure. Conversely, too little tension can result in excessive sag, which can create dangerous clearance issues.

• Clearance: This is the minimum required distance between the energized conductor and the ground, buildings, roads, or other objects. Maintaining proper clearance is a fundamental safety requirement mandated by regulations to prevent electrical shock, fires, and other hazards.

While some of these measurements can be estimated with traditional visual methods, using specialized equipment is crucial for accuracy and safety. Ningbo Changshi offers a range of tools designed for these precise measurements.

• For Sag and Tension: Our hydraulic puller and tensioner machines are equipped with advanced control systems and can maintain and display precise tension during the stringing process. For post-installation checks, we offer tension meters and sag measurement devices that can be used to verify the line's mechanical state.

• For Clearance: While laser measurement devices and ultrasonic measuring tools are popular for remote, non-contact measurements, we also supply essential measuring tapes and measuring rods for more direct, de-energized work. These tools are often used in conjunction with other methods to ensure compliance with local safety codes.

• Modern Methods: Modern utility companies are increasingly using drones equipped with LiDAR (Light Detection and Ranging) and high-resolution cameras. These tools create detailed 3D models of the power line and its surroundings, allowing for highly accurate sag and clearance measurements from a safe distance.