Professional Answer: High voltage cables are highly sensitive to stress. The specialized equipment we manufacture is specifically designed to protect the cable's core and insulation, which are crucial for its long-term performance.

• Controlled Tension: A hydraulic puller ensures the pulling force never exceeds the cable's rated maximum tension, preventing stretching or internal damage.

• Proper Bending Radius: The large bullwheel diameters on our stringing blocks and tensioners are engineered to prevent sharp bends, which can cause permanent damage to the insulation and semi-conducting layers.

• Reduced Friction: Using purpose-built rollers and guides minimizes friction during the pull, which further reduces the required pulling tension and protects the cable's outer sheath from abrasion.

Professional Answer: While both applications require immense force and precision, the equipment is tailored to the specific environment.

• Overhead Stringing Equipment: The focus here is on puller-tensioner systems. These machines work in tandem on opposite ends of the line section to string conductors with controlled tension, ensuring correct sag and preventing ground contact.

• Underground Laying Equipment: For underground projects, the primary machine is a hydraulic winch or puller used in conjunction with cable feeders. Winches provide the immense force needed to pull cables through ducts, while feeders assist in pushing the cable from the reel stand, easing the load on the pulling equipment and the cable itself.

Professional Answer: Pulling cables through conduits presents unique challenges that are often not an issue with open-air installations. The primary challenges are:

• Friction: This is the number one obstacle. The long surface area of the cable rubbing against the interior of the conduit can generate immense friction, requiring a very high pulling force.

• Conduit Bends: Each bend or corner in a conduit dramatically increases friction and can create damaging sidewall pressure on the cable.

• Conduit Obstructions: Debris, water, or damaged sections within the conduit can cause the cable to jam, leading to project delays or, worse, cable damage.

• Limited Space: The confined space inside a conduit makes it difficult to manage the cable, increasing the risk of kinking or twisting.

Professional Answer: A successful HV pull relies on more than just the main machines. The right accessories are equally vital. At Ningbo Changshi, we manufacture and supply a full range of high-quality accessories, including:

• High-Strength Pulling Grips: These are specifically designed to securely grip the conductor without damaging it.

• Anti-Twist Swivels: These are essential to prevent the pulling rope from twisting the conductor, which can cause internal stress.

• Reel Stands and Jacks: For holding the heavy cable drums securely.

• Pulling Ropes: We provide high-strength, low-stretch ropes to ensure a consistent and safe pull.

• Professional Answer: Minimizing friction is crucial for a safe and successful pull. Our equipment and best practices at Ningbo Changshi are designed for this purpose:

  • Use a Professional Cable Pulling Lubricant: A high-quality lubricant is essential to reduce the friction coefficient between the cable and the conduit. Our recommended lubricants are specifically formulated for this task.

  • Use a Cable Feeder: A cable feeder assists by pushing the cable into the conduit at a controlled speed, which significantly reduces the pulling tension required at the other end.

  • Properly Sized Sheaves: Our underground cable rollers and sheaves are designed to maintain the cable’s minimum bending radius at conduit entrances and exits, preventing kinking and minimizing damage.

• Professional Answer: For heavy, long-distance pulls in conduit, manual labor is not a safe or efficient option. We recommend a system that combines power and precision. The essential equipment includes:

  • Hydraulic Cable Pulling Machine: Our hydraulic pullers provide the immense and consistent pulling force needed to overcome friction while offering precise tension control to protect the cable.

  • Cable Feeder: As mentioned above, a cable feeder is a vital component for reducing tension and making the pull easier and safer.

  • Cable Guides and Rollers: Used at every change of direction, our specialized rollers and sheaves prevent damage and ensure a smooth path for the cable.

  • Tension Recorder: Our advanced pullers come with integrated recorders that log the pulling tension in real-time. This provides a critical record that the cable was installed within its specified tension limits, which is often required for warranty and quality assurance.

Professional Answer: An industrial cable pulling machine is a powerful piece of equipment designed to automate and mechanize the process of installing heavy cables or conductors. Its primary purpose is to apply a high and controlled pulling force to safely and efficiently pull cables over long distances, through conduits, or across elevated structures. This machinery is essential for large-scale projects, such as:

• Overhead Transmission Line (OHTL) Construction: Pulling steel pilot ropes or conductors across towers.

• Underground Electrical Work: Pulling power cables through ducts and conduits in a safe and controlled manner.

Professional Answer: Proper planning is the most important step in preventing complications. Before you start pulling, our experts at Ningbo Changshi advise:

• Calculate Tension: Use software to calculate the anticipated pulling tension based on the conduit run, number of bends, and cable weight. This helps you select the correct equipment and rope.

• Inspect the Conduit: Ensure the conduit is clean and free of any sharp edges or debris that could damage the cable.

• Choose the Right Pulling Grip: Select a high-quality cable pulling grip sock that is correctly sized for your cable to ensure a secure connection that won’t slip or damage the cable’s jacket.

Professional Answer: At Ningbo Changshi, we offer a range of industrial cable pulling machines designed for different power sources and applications. The most common types are:

• Hydraulic Pullers: These are our flagship machines. They use a hydraulic system for precise control of pulling tension and speed, making them ideal for high-voltage and delicate conductor stringing where accuracy is critical.

• Engine-Powered Winches: These are robust machines that use a gasoline or diesel engine to provide the necessary power. They are perfect for heavy-duty underground cable pulling where high force is required over a long distance.

• Electric Pullers: These are typically used for smaller-scale industrial applications or when a dedicated power source is available. They are known for their quiet operation and ease of use.

Professional Answer: While manual labor can be used for small cables, industrial-grade projects demand the use of a machine for significant benefits in safety, efficiency, and cost.

• Improved Safety: The high forces involved in pulling heavy cables manually can lead to severe ergonomic injuries and accidents. A machine automates this process, significantly reducing the risk of injury.

• Increased Efficiency: Our machines can pull cables at a consistent speed and force, completing installations in a fraction of the time it would take with a manual crew, which dramatically reduces labor hours.

• Prevents Cable Damage: The precise tension and speed control of an industrial puller ensures that the cable's maximum tension limit is never exceeded. This prevents stretching, kinking, or damage to the insulation, preserving the cable's integrity and extending its service life.

Professional Answer: Selecting the right machine is a critical decision. We recommend considering the following factors:

• Required Pulling Force: Determine the maximum pulling force your project requires to overcome friction and gravity.

• Cable Type and Weight: Heavier and more sensitive cables (like HV cables) require more powerful machines with a higher degree of control.

• Project Environment: Will the machine be used in a remote location where an engine-powered unit is best, or on a site with a ready power source?

• Budget and Usage Frequency: While the initial cost of a machine is higher than that of hiring, a machine will quickly pay for itself through increased efficiency and reduced labor costs. Our team at Ningbo Changshi is ready to help you choose the ideal industrial cable pulling machine to meet your specific project needs.

• Professional Answer: At Ningbo Changshi, we manufacture two main types of professional-grade cable reel jack stands, each suited for different project needs:

  • Hydraulic Cable Reel Jack Stands: These are our most popular heavy-duty stands. They use a powerful hydraulic cylinder to effortlessly lift extremely heavy cable drums, often with a capacity of 5 tons or more. They are the ideal choice for large-scale projects involving heavy, high-voltage cables where safety and ease of use are paramount.

  • Screw-Type Cable Reel Jack Stands: These stands use a manual screw mechanism to lift the drum. They are a reliable and economical option for smaller to medium-sized cable drums where the pulling load is less demanding. They are known for their durability and low maintenance. The best choice for your project depends on the weight and size of your cable drums and the specific requirements of the job.

Professional Answer: To ensure a safe and efficient installation, you should always choose cable jack stands with the following features:

• High Load-Bearing Capacity: Ensure the stands are rated to safely support the full weight of your heaviest cable drum.

• Adjustable Height and Width: The stands should be easily adjustable to accommodate a wide range of reel diameters and widths, providing versatility for various projects.

• Robust Construction: Look for stands made from high-strength steel with a durable finish, designed to withstand rugged on-site conditions.

• Integrated Safety Mechanisms: High-quality stands, such as ours, feature safety pins and secure axle locking systems to prevent the drum from accidentally falling.

Professional Answer: While both are used for paying out cable, cable jack stands and reel rollers serve different purposes.

• Cable Jack Stands are the superior choice for heavy-duty applications and for handling very large or wide cable reels. They provide a stable, elevated platform that is crucial for keeping the cable aligned with overhead lines or underground conduits.

• Reel Rollers are single-piece platforms with rollers that the cable reel sits on. They are more suitable for lighter cable drums and for jobs where the cable reel needs to be easily moved and repositioned frequently. For most industrial and utility projects, jack stands are the go-to solution due to their superior load capacity, stability, and safety features.

Professional Answer: A professional cable pulling procedure is a systematic process designed to ensure safety and prevent costly cable damage. Our recommended procedure follows four main phases:

1. Pre-Pull Planning: This is the most critical phase. It involves calculating pulling tension, inspecting the route, and preparing all necessary safety documentation and a pulling plan.

2. Site & Equipment Setup: Securely position all equipment, including the cable drum jack stands and the hydraulic puller. The pulling rope is then fed through the route.

3. The Pull: The actual pulling of the cable begins. This phase is monitored in real-time to ensure the pulling tension and speed remain within safe limits.

4. Post-Pull Completion: Once the pull is complete, the cable is terminated, and all equipment is safely secured and prepared for the next task.

Professional Answer: Proper pre-pull planning is essential to prevent equipment failure, project delays, and most importantly, damage to expensive cables. The most necessary calculation is determining the maximum pulling tension. Factors considered include:

• Cable Weight: The total weight of the cable being pulled.

• Coefficient of Friction: The friction created between the cable and the inner surface of the conduit or stringing blocks.

• Number of Bends: Each bend significantly increases friction and tension. Our engineers at Ningbo Changshi use these calculations to recommend the precise equipment and accessories—such as specialized lubricants and cable feeders—that will ensure the pull remains safe and efficient.

Professional Answer: The setup phase is where a well-planned procedure is executed with the right tools. Each piece of equipment plays a specific role:

• Cable Drum Jack Stands: These stands safely and securely lift the heavy cable reel off the ground, allowing it to pay out smoothly without binding or toppling.

• Conduit Rollers & Guides: These are strategically placed at all bends and entry/exit points to support the cable and maintain its minimum bending radius, preventing kinking and damage to the insulation.

• Pulling Rope and Grip: A high-strength, low-stretch pulling rope is attached to the cable via a correctly sized cable pulling grip and swivel, ensuring a secure and twist-free connection.

Professional Answer: The "pull" phase is where the plan comes to life, and a focus on safety and real-time monitoring is paramount.

• Maintain a Safe Distance: All personnel should be kept out of the line of fire of the pulling rope and cable.

• Real-Time Monitoring: Our hydraulic cable pulling machines are equipped with an integrated tension recorder that provides real-time feedback on the pulling force. This allows the operator to instantly adjust the speed to prevent exceeding the cable's maximum allowable tension.

• Lubrication: A professional cable lubricant should be applied consistently to the cable as it enters the conduit, further reducing friction and making the pull smoother.

A successful low voltage (LV) cable pull requires a combination of basic hand tools and specialized equipment to ensure the job is done safely and efficiently. While many manual tools exist, for long runs or multiple cables, professional-grade equipment is necessary. The essential tools from our comprehensive supply include:

• Cable Pullers/Winch: For runs of more than a few meters, a powered cable puller or winch is a non-negotiable tool. Our hydraulic pullers are scaled down for LV applications, providing controlled force that prevents damage to the cable.

• Fish Tapes and Rods: These are indispensable for feeding a pilot rope or string through conduits and wall cavities. We offer various lengths and materials, including non-conductive fiberglass rods for safety.

• Cable Pulling Grips: Also known as cable socks, these are woven wire mesh tubes that securely attach the pulling rope to the cable. Using the correct size and type is vital to prevent the cable from slipping or being damaged.

• Cable Rollers and Guides: These accessories are used to guide the cable around corners and turns, significantly reducing friction and protecting the cable's jacket from abrasion.