The pulling tension for a 132kV cable must be meticulously managed to protect its integrity. It is determined by the cable's conductor material and total cross-sectional area, and it is calculated using the same fundamental formula as lower-voltage cables, but with a heightened emphasis on precision.

The maximum pulling tension (Tmax) is calculated as:

Tmax=K×S

• K is the constant for the conductor material (50N/mm2 for copper; 30N/mm2 for aluminum).

• S is the total cross-sectional area of the conductors in mm2.

For 132kV installations, the process goes a step further. We recommend our puller-tensioners that feature an automatic overload protection system. If the pulling tension approaches a pre-set limit, the machine automatically slows down or stops the pull, preventing dangerous over-tensioning and protecting the cable from irreversible damage.

When you choose to hire, it's crucial to select a winch that is safe and reliable. Beyond checking the rental cost, you should ask the following questions:

• Is the winch regularly serviced and certified? A professional rental company should be able to provide records of recent inspections and maintenance to ensure the equipment is in perfect working order.

• Does the winch have a real-time tension monitoring system? For safe pulling, a winch must have an integrated tension meter to prevent over-pulling and cable damage.

• Does the rental include all necessary accessories? The winch is only one part of the system. Check if the rental includes the pulling rope, proper cable grips, and any required rollers or sheaves.

• Is technical support available? A reputable rental company should offer expert support and guidance on how to use the equipment safely and efficiently.

A 10-ton (100 kN) cable pulling winch is a heavy-duty machine designed for large-scale, complex projects that exceed the capacity of standard winches. The primary applications for this level of pulling force include:

• High-Voltage (HV) Cable Installation: Pulling thick, heavy conductors for high-voltage (132kV, 220kV, 400kV) overhead transmission lines and underground power systems.

• Long-Distance Underground Feeds: Installing power cables over several kilometers through conduits or trenches, where friction and cable weight accumulate to require substantial pulling force.

• Heavy Industrial and Marine Applications: Pulling very large diameter cables in industrial plants, shipyards, or large-scale mining operations.

• Multi-Conductor Pulls: Pulling multiple bundled conductors at once for high-capacity lines, a process that generates immense tension.

Installing 11kV cable is a high-risk operation that demands strict safety protocols. The primary concerns are the cable's high voltage and its weight. Key precautions include:

• De-energization and Lockout/Tagout: Before any work begins, the circuit must be de-energized, tested, and properly locked out and tagged out to prevent accidental re-energization.

• Insulation and Grounding: All personnel must use appropriate personal protective equipment (PPE), including insulated gloves, boots, and tools. Temporary grounding must be installed to safely discharge any residual voltage.

• Controlling Pulling Tension: Excessive tension can damage the cable's insulation, which can lead to a future catastrophic failure. It is non-negotiable to use a winch with a real-time tensiometer to monitor the pulling force.

• Proper Handling: The cable must be handled with care to avoid kinking or sharp bends that could compromise its insulation. Proper cable rollers and sheaves are essential for guiding the cable smoothly through the route.

A professional-grade 10-ton winch is more than just a powerful motor; it's a sophisticated machine with features that ensure precision, safety, and efficiency. The most critical features to look for are:

• Closed Hydraulic Circuit: A closed-loop hydraulic system provides step-less speed variation in both forward and reverse directions. This allows the operator to precisely control the pull, even at speeds as low as 0 m/min, which is crucial for navigating obstacles and preventing over-tensioning.

• Integrated Electronic Tensiometer: This feature is essential for safety. The tensiometer provides real-time digital readings of the pulling force. Our machines come with an automatic pull force pre-setting system that will automatically adjust the operation speed to maintain the pre-set value, protecting the cable from damage.

• Diesel Engine: For this capacity, a powerful and reliable diesel engine is standard. It provides the necessary power for continuous, heavy-duty operation in any remote location without access to a power grid.

• Automatic Rope Winder: An automatic rope winder ensures that the steel rope is layered evenly and neatly on the drum. This prevents tangles, minimizes wear on the rope, and increases the overall efficiency and safety of the pull.

While a lower-capacity winch may be cheaper, it is not a viable solution for heavy-duty projects. A 10-ton winch is a better investment for these reasons:

• Safety Margin: Attempting to use an undersized winch for a heavy pull is extremely dangerous. It puts excessive strain on the machine, increasing the risk of equipment failure, rope breakage, and serious injury.

• Efficiency: A 10-ton winch is engineered to handle heavy loads with a higher speed and efficiency, significantly reducing project completion time and labor costs.

• Longevity: Our 10-ton winches are built with heavy-duty components designed to withstand continuous high-tension use, ensuring a long operational lifespan and a strong return on your investment.

A 10-ton (100 kN) cable pulling machine is a heavy-duty piece of equipment designed for large-scale, complex projects that exceed the capacity of standard winches. The primary applications for this level of pulling force include:

• High-Voltage (HV) Cable Installation: Pulling thick, heavy conductors for high-voltage (132kV, 220kV, 400kV) overhead transmission lines and underground power systems.

• Long-Distance Underground Feeds: Installing power cables over several kilometers through conduits or trenches, where friction and cable weight accumulate to require substantial pulling force.

• Heavy Industrial and Marine Applications: Pulling very large diameter cables in industrial plants, shipyards, or large-scale mining operations.

• Multi-Conductor Pulls: Pulling multiple bundled conductors at once for high-capacity lines, a process that generates immense tension.

A professional-grade 10-ton winch is more than just a powerful motor; it's a sophisticated machine with features that ensure precision, safety, and efficiency. The most critical features to look for are:

• Closed Hydraulic Circuit: A closed-loop hydraulic system provides step-less speed variation in both forward and reverse directions. This allows the operator to precisely control the pull, even at speeds as low as 0 m/min, which is crucial for navigating obstacles and preventing over-tensioning.

• Integrated Electronic Tensiometer: This feature is essential for safety. The tensiometer provides real-time digital readings of the pulling force. Our machines come with an automatic pull force pre-setting system that will automatically adjust the operation speed to maintain the pre-set value, protecting the cable from damage.

• Diesel Engine: For this capacity, a powerful and reliable diesel engine is standard. It provides the necessary power for continuous, heavy-duty operation in any remote location without access to a power grid.

• Automatic Rope Winder: An automatic rope winder ensures that the steel rope is layered evenly and neatly on the drum. This prevents tangles, minimizes wear on the rope, and increases the overall efficiency and safety of the pull.

While a lower-capacity winch may be cheaper, it is not a viable solution for heavy-duty projects. A 10-ton winch is a better investment for these reasons:

• Safety Margin: Attempting to use an undersized winch for a heavy pull is extremely dangerous. It puts excessive strain on the machine, increasing the risk of equipment failure, rope breakage, and serious injury.

• Efficiency: A 10-ton winch is engineered to handle heavy loads with a higher speed and efficiency, significantly reducing project completion time and labor costs.

• Longevity: Our 10-ton winches are built with heavy-duty components designed to withstand continuous high-tension use, ensuring a long operational lifespan and a strong return on your investment.

Proper preparation is the most critical factor in a successful cable pull. Skipping these steps can lead to costly delays and damage to the cable. The key steps include:

• Inspection and Cleaning: Visually inspect the conduit for any debris, sharp edges, or blockages. Use a conduit swab or mandrel to clean the inside of the conduit. For underground conduits, a duct prover is essential to ensure the conduit is clear and properly aligned.

• Lubrication: Use a professional-grade wire-pulling lubricant to reduce friction. Apply it liberally to the cable as it enters the conduit, especially for long pulls or runs with multiple bends. This is a low-cost step that dramatically reduces the pulling tension.

• Establishing a Pull String: Before the cable pull, you must first get a pull string or mule tape through the conduit. A conduit mouse and a shop vacuum are an effective combination for this task. Once the string is through, you can use it to pull the heavier mule tape or pulling rope.

The type and size of the conduit are major determinants of the pull's difficulty and required equipment.

• Conduit Size (Fill Ratio): The National Electrical Code (NEC) provides strict guidelines on the maximum number of conductors a conduit can hold. The fill ratio—the percentage of the conduit's cross-sectional area occupied by the cables—is crucial. Overfilling a conduit increases friction, making the pull more difficult and potentially damaging the cable insulation. It also leads to poor heat dissipation, which can be a fire hazard. We always recommend using a conduit fill calculator during the planning phase.

• Conduit Type and Bends: Different materials, such as PVC, EMT, or rigid metal, have varying friction coefficients. A rigid metal conduit generally offers a smoother pull than PVC. The number of bends, especially 90-degree bends, exponentially increases friction and tension. The "360-degree rule" states that the total of all bends in a single pull should not exceed 360 degrees.

Manholes serve as crucial access points for long-distance underground pulls. A proper setup here can make or break a project.

• Positioning and Equipment: A pulling winch should be set up at the exit manhole, securely anchored to withstand the high pulling tension. The feed manhole should be equipped with cable rollers and manhole sheaves to support the cable's weight and guide it smoothly around corners, maintaining the proper bending radius.

• Reducing Sidewall Pressure: Pulling a heavy cable through a bend in a manhole generates immense "sidewall pressure," a crushing force that can damage the cable. Using appropriately sized sheaves and rollers redirects this force away from the cable, ensuring its integrity.

• Communication: A crucial, yet often overlooked, part of the setup is clear communication. With workers at the winch, at the feed end, and often at intermediate manholes, a reliable communication system is essential for coordinating the pull and stopping immediately if an issue arises.

Pulling a 400kV cable is a highly complex and hazardous operation due to its immense size, weight, and the severe consequences of a mistake. The key factors that elevate the challenge are:

• Extreme Weight and Size: 400kV cables are exceptionally heavy, often requiring pulling forces of 10 tons (100 kN) or more. The sheer weight and stiffness of the cable demand equipment with a pulling capacity and control far beyond a standard winch.

• Insulation Integrity: The cable's insulation is incredibly sensitive. Any damage—from excessive tension, an incorrect bending radius, or abrasion—can create a defect that may lead to a catastrophic electrical failure years after installation.

• Safety Zone & Flashover Risk: Working with EHV cables requires strict adherence to safety clearances. The risk of flashover—where electricity arcs through the air—is a serious and fatal concern. All equipment and personnel must remain a specified safe distance from the energized line at all times.

The installation of a 400kV cable requires a system of interconnected, high-precision equipment. Relying on standard tools is not an option.

• High-Capacity Puller-Tensioner: A hydraulic, diesel-powered puller-tensioner with a capacity of 10 tons or more is essential. The machine must provide a smooth, consistent pulling force and must be capable of a closed hydraulic circuit to prevent any sudden changes in speed or tension.

• Automated Tension Monitoring: A built-in, electronic tensiometer with an automated tension control system is a non-negotiable safety feature. It provides real-time data and can be programmed to automatically stop the pull if the tension exceeds a pre-set limit, protecting the cable from damage.

• Heavy-Duty Cable Drum Stands: The drums holding 400kV cables are colossal, often weighing tens of tons. Hydraulic drum jacks with sufficient load capacity and a robust spindle bar are required to safely lift and unspool the drum.

• Precision Rollers and Sheaves: The cable must be guided smoothly along the entire route. This requires a full set of heavy-duty conduit rollers, corner sheaves, and manhole sheaves, specifically designed to support the cable's weight and maintain its minimum bending radius.

The pulling tension for a 400kV cable must be calculated with extreme precision during the project's design phase. It's determined by the cable's conductor material and total cross-sectional area.

The maximum permissible tension (Tmax) is calculated as:

• Tmax is the maximum allowable pulling tension.

• K is the constant for the conductor material (50N/mm2 for copper; 30N/mm2 for aluminum).

• S is the total cross-sectional area of the conductors in mm2.

In addition to this calculation, other factors must be considered, such as the coefficient of friction (which can be reduced with professional lubricant), the number of bends, and the sidewall pressure the cable will experience when pulled around bends. Our puller-tensioners feature advanced electronic control systems that can be programmed with these values to ensure the pull never exceeds the calculated limits.

5-ton (50 kN) cable pulling machine is the most versatile solution for a vast number of projects, striking an ideal balance between power and portability. The most common applications include:

• Medium-Voltage (MV) Cable Installation: This capacity is perfect for pulling 11kV, 22kV, and 33kV power cables in underground conduits, where friction and cable weight require significant force.

• Telecommunications and Fiber Optic Networks: It provides the necessary power for longer-distance pulls of heavy copper or large bundles of fiber optic cables.

• Overhead Transmission Line Stringing: It is used for stringing smaller to medium-sized conductors on overhead power lines, including pilot wires and smaller ACSR conductors.

• Heavy Industrial and Commercial Construction: This machine is ideal for pulling large-diameter electrical cables through conduits and trays within factories, large buildings, and sub-stations.

The primary difference is the rated pulling capacity, which dictates the size and scope of the projects each machine can handle.

• 5-Ton Machine: This machine is a medium-duty workhorse, perfect for standard underground and overhead power projects. It is typically more compact, lighter, and more cost-effective. Its pulling force is ideal for single-conductor pulls of medium-sized cables or for shorter, straight pulls of heavier cables.

• 10-Ton Machine: This is a heavy-duty machine designed for large-scale, high-tension jobs. It's required for projects involving extra-high voltage (EHV) cables, very long-distance pulls, or when pulling multiple conductors simultaneously. These machines are larger, heavier, and include more advanced features like greater drum capacity and enhanced cooling systems.

Choosing the right size is crucial for both safety and efficiency. Using a 5-ton machine on a project that requires a 10-ton pull is unsafe and can lead to equipment failure.

A 5-ton (50 kN) cable pulling winch is the most versatile solution for a vast number of projects, striking an ideal balance between power and portability. The most common applications include:

• Medium-Voltage (MV) Cable Installation: This capacity is perfect for pulling 11kV, 22kV, and 33kV power cables in underground conduits, where friction and cable weight require significant force.

• Telecommunications and Fiber Optic Networks: It provides the necessary power for longer-distance pulls of heavy copper or large bundles of fiber optic cables.

• Overhead Transmission Line Stringing: It is used for stringing smaller to medium-sized conductors on overhead power lines, including pilot wires and smaller ACSR conductors.

• Heavy Industrial and Commercial Construction: This machine is ideal for pulling large-diameter electrical cables through conduits and trays within factories, large buildings, and substations.

A high-quality 5-ton winch from Ningbo Changshi is built for reliability and operator safety. Here are the most essential features:

• Hydraulic Drive System: We recommend a hydraulic winch over a mechanical one for this capacity. A hydraulic drive provides smooth, stepless speed control, which is vital for preventing cable damage from sudden jerks or stops.

• Real-Time Tensiometer: An integrated tensiometer is a crucial safety feature. It provides an immediate digital reading of the pulling force, allowing the operator to ensure the tension does not exceed the cable manufacturer's specifications.

• Overload Protection: Our 5-ton winches include an automatic overload protection system. If the pulling force approaches a pre-set limit, the machine will automatically reduce speed or stop the pull, protecting the cable and the equipment.

• Compact and Mobile Design: A well-designed 5-ton winch should be mounted on a sturdy chassis with wheels, making it easy to transport and maneuver on a job site.