Introduction | 简介

In industrial applications involving monospiral drum operations, mobile mining equipment, and trailing cable systems, cables undergo continuous mechanical flexing that directly impacts their operational lifespan. The (N)TSCGEWÖU cable, designed specifically for demanding reeling and unreeling operations in mining and heavy industry, must demonstrate exceptional flex endurance to ensure reliable power transmission throughout its service life. This technical document examines how the standardized two-pulley flexing test according to BS EN 50396 and IEC 60245 standards accurately simulates real-world cable life cycles and validates the mechanical durability of these critical power transmission components.

在涉及单螺旋卷筒操作、移动采矿设备和拖曳电缆系统的工业应用中，电缆经历持续的机械挠曲，直接影响其使用寿命。(N)TSCGEWÖU电缆专为采矿和重工业中要求严格的收卷和放卷操作而设计，必须表现出卓越的挠曲耐久性，以确保在整个使用寿命期间可靠的电力传输。本技术文件研究了根据BS EN 50396和IEC 60245标准的标准化双滑轮挠曲测试如何准确模拟真实世界的电缆生命周期，并验证这些关键电力传输组件的机械耐久性。

Understanding Cable Flexing and Life Cycle Simulation | 理解电缆挠曲和生命周期模拟

Cable flexing refers to the repeated bending and straightening motion that cables experience during operational use. For reeling cables used on drum systems, this flexing occurs thousands of times daily as equipment moves, drums rotate, and cables are wound and unwound. Each complete cycle of winding and unwinding subjects the cable to mechanical stress that gradually affects the conductor strands, insulation integrity, and sheath materials. The cumulative effect of these repeated stress cycles determines the cable’s practical service life in real-world applications.

电缆挠曲是指电缆在操作使用期间经历的反复弯曲和拉直运动。对于卷筒系统上使用的卷筒电缆，随着设备移动、卷筒旋转以及电缆收卷和放卷，这种挠曲每天发生数千次。每次完整的收卷和放卷循环都会使电缆承受机械应力，逐渐影响导体股线、绝缘完整性和护套材料。这些重复应力循环的累积效应决定了电缆在实际应用中的实际使用寿命。

The two-pulley flexing test apparatus provides a controlled laboratory environment that accurately replicates the mechanical stresses experienced by reeling cables in service. By subjecting cable samples to precisely defined flexing motions under load, the test generates accelerated aging data that predicts long-term performance and identifies potential failure modes before cables are deployed in critical applications. This predictive capability is essential for ensuring operational safety and minimizing costly equipment downtime.

双滑轮挠曲测试装置提供了一个受控的实验室环境，准确复制卷筒电缆在使用中经历的机械应力。通过在负载下对电缆样品进行精确定义的挠曲运动，测试生成加速老化数据，预测长期性能并识别潜在的失效模式，然后再将电缆部署到关键应用中。这种预测能力对于确保操作安全和最小化昂贵的设备停机时间至关重要。

The Two-Pulley Flexing Test Standard: BS EN 50396 | 双滑轮挠曲测试标准：BS EN 50396

The two-pulley flexing test is comprehensively defined in BS EN 50396, the European standard for “Non electrical test methods for low voltage energy cables.” This standard establishes rigorous mechanical testing procedures specifically designed to evaluate the durability and reliability of flexible cables subjected to repetitive bending under operational conditions. The test applies to multicore thermoplastic cables with conductor cross-sectional areas less than 2.5mm² and multicore cross-linked cables with areas less than 4mm², although modified parameters can be applied to larger cables including medium-voltage mining cables like (N)TSCGEWÖU.

双滑轮挠曲测试在BS EN 50396中有全面定义，这是”低压能源电缆的非电气测试方法”的欧洲标准。该标准建立了严格的机械测试程序，专门设计用于评估在操作条件下受到重复弯曲的柔性电缆的耐久性和可靠性。该测试适用于导体横截面积小于2.5mm²的多芯热塑性电缆和横截面积小于4mm²的多芯交联电缆，尽管可以将修改的参数应用于更大的电缆，包括像(N)TSCGEWÖU这样的中压采矿电缆。

The corresponding international standard IEC 60245-2 “Rubber insulated cables – Test methods” also specifies flexing test procedures that align with BS EN 50396 methodologies. These standards are recognized globally and form the technical basis for cable certification by organizations including VDE (Verband der Elektrotechnik), BASEC (British Approvals Service for Cables), and other national certification bodies. Compliance with these testing standards provides manufacturers and end-users with objective, quantifiable evidence of cable performance under flexing conditions.

相应的国际标准IEC 60245-2″橡胶绝缘电缆-测试方法”也规定了与BS EN 50396方法一致的挠曲测试程序。这些标准在全球范围内得到认可，构成了VDE（德国电气技术协会）、BASEC（英国电缆批准服务）和其他国家认证机构进行电缆认证的技术基础。符合这些测试标准为制造商和最终用户提供了客观、可量化的证据，证明电缆在挠曲条件下的性能。

Two-Pulley Flexing Test Apparatus and Setup | 双滑轮挠曲测试装置和设置

Test Equipment Configuration | 测试设备配置

The two-pulley flexing test apparatus consists of several critical components that work together to simulate realistic cable operating conditions. The system includes a movable carriage (designated as ‘C’ in standard diagrams) that supports two rotating pulley wheels of specified diameter. These pulleys are mounted on the carriage which traverses horizontally along precision rails. Two additional fixed pulleys are positioned at either end of the apparatus, creating a four-pulley system through which the cable sample travels during testing. All four pulleys must be carefully aligned to ensure the cable sample remains horizontal throughout the test cycle, preventing unintended torsional stress that could skew results.

双滑轮挠曲测试装置由几个关键组件组成，这些组件共同模拟真实的电缆操作条件。该系统包括一个可移动托架（在标准图中指定为”C”），支撑两个指定直径的旋转滑轮。这些滑轮安装在托架上，托架沿精密导轨水平移动。两个额外的固定滑轮位于装置的两端，创建一个四滑轮系统，电缆样品在测试期间通过该系统。所有四个滑轮必须仔细对齐，以确保电缆样品在整个测试周期中保持水平，防止可能扭曲结果的意外扭转应力。

Cable Sample Preparation | 电缆样品准备

Test samples typically consist of cable sections measuring five meters in length. The cable is wound around the pulley system in a serpentine pattern, with the middle section of the cable passing over the two movable pulleys on the carriage while the ends extend to the fixed pulleys at each end of the test rig. Specified weights are attached to both ends of the cable sample to simulate the mechanical tension that reeling cables experience during operational deployment. These weights are carefully calculated based on cable diameter, construction type, and intended application, with specific values defined in the relevant standard specifications.

测试样品通常由长度为五米的电缆段组成。电缆以蛇形模式缠绕在滑轮系统周围，电缆的中间部分通过托架上的两个可移动滑轮，而两端延伸到测试装置两端的固定滑轮。在电缆样品的两端附加指定的重量，以模拟卷筒电缆在操作部署期间经历的机械张力。这些重量根据电缆直径、结构类型和预期应用仔细计算，具体值在相关标准规范中定义。

Test Execution and Monitoring Procedures | 测试执行和监控程序

Dynamic Flexing Cycle | 动态挠曲周期

During test execution, the motorized carriage moves continuously back and forth along its one-meter travel path at the specified speed of approximately 0.33 meters per second. Each complete forward and backward movement constitutes one flexing cycle. This cyclical motion causes the cable to alternately bend around the pulleys and straighten as the carriage traverses its full range of motion. The bending action subjects different sections of the cable to varying mechanical stresses: the outer radius of each bend experiences tensile elongation while the inner radius undergoes compression, precisely mimicking the stress patterns that occur during real-world drum reeling operations.

在测试执行期间，电动托架以大约0.33米/秒的指定速度沿其一米行程路径连续来回移动。每次完整的前后移动构成一个挠曲周期。这种循环运动导致电缆在托架穿过其全部运动范围时交替围绕滑轮弯曲和拉直。弯曲动作使电缆的不同部分承受不同的机械应力：每个弯曲的外半径经历拉伸伸长，而内半径经历压缩，精确模拟在真实世界卷筒收卷操作期间发生的应力模式。

Electrical Continuity Monitoring | 电气连续性监控

Throughout the entire 30,000-cycle test duration, the cable operates under its rated electrical load. Sophisticated monitoring equipment continuously checks for any electrical failures including open circuits (conductor breakage), short circuits between individual conductors, or insulation breakdown between conductors and the grounded test frame. This real-time electrical monitoring is critical because mechanical damage to conductors or insulation often manifests as electrical faults before visible physical deterioration becomes apparent. The monitoring system instantly detects and records any electrical anomaly, providing precise data about when and how failures occur during the flex cycle progression.

在整个30,000个周期的测试期间，电缆在其额定电气负载下运行。精密的监控设备连续检查任何电气故障，包括开路（导体断裂）、单个导体之间的短路或导体与接地测试框架之间的绝缘击穿。这种实时电气监控至关重要，因为导体或绝缘的机械损坏通常在可见的物理劣化变得明显之前表现为电气故障。监控系统立即检测并记录任何电气异常，提供关于在挠曲周期进展期间何时以及如何发生故障的精确数据。

Pass/Fail Criteria and Performance Evaluation | 合格/不合格标准和性能评估

Acceptance Standards | 验收标准

To successfully pass the two-pulley flexing test according to BS EN 50396 standards, the cable sample must complete all 30,000 flexing cycles without experiencing any electrical failure. Specifically, the monitoring equipment must not detect any open circuits, short circuits between conductors, or short circuits between any conductor and the grounded test apparatus. The cable must maintain continuous electrical conductivity throughout the entire test duration, demonstrating that its internal conductor structure remains intact despite repeated mechanical flexing stress.

要根据BS EN 50396标准成功通过双滑轮挠曲测试，电缆样品必须完成所有30,000个挠曲周期，而不会经历任何电气故障。具体来说，监控设备不得检测到任何开路、导体之间的短路或任何导体与接地测试装置之间的短路。电缆必须在整个测试期间保持连续的电气导电性，证明其内部导体结构尽管经历反复的机械挠曲应力仍保持完整。

Post-Test Verification | 测试后验证

Following successful completion of the 30,000-cycle flexing test, additional verification tests may be conducted as specified by the particular cable standard. For example, BS EN 50525 specifies that individual cable cores should be stripped from the tested sample, immersed in a water bath maintained at 20°C, and subjected to a voltage withstand test at 2000V for 15 minutes. This post-flexing insulation integrity test verifies that the repeated mechanical stress has not compromised the insulation’s dielectric properties, ensuring the cable maintains its electrical safety characteristics even after extensive flexing.

在成功完成30,000周期挠曲测试后，可以按照特定电缆标准的规定进行额外的验证测试。例如，BS EN 50525规定应从测试样品中剥离单个电缆芯线，浸入保持在20°C的水浴中，并在2000V下进行耐压测试15分钟。这种挠曲后绝缘完整性测试验证了反复的机械应力没有损害绝缘的介电性能，确保电缆即使在广泛的挠曲后仍保持其电气安全特性。

Visual Inspection Requirements | 目视检查要求

In addition to electrical testing, comprehensive visual examination of the cable after flexing reveals important information about physical deterioration. Inspectors examine the outer sheath for cracks, abrasion wear, or surface damage. The cable is also checked for any signs of jacket twisting, which would indicate improper conductor construction or inadequate internal component design. For cables that successfully complete the electrical portion of the test, visual inspection confirms that external protective layers have maintained their structural integrity, providing continued protection against environmental hazards in service.

除电气测试外，挠曲后电缆的全面目视检查揭示了有关物理劣化的重要信息。检查员检查外护套是否有裂纹、磨损或表面损坏。还检查电缆是否有任何护套扭转的迹象，这将表明导体结构不当或内部组件设计不足。对于成功完成测试电气部分的电缆，目视检查确认外部保护层保持了其结构完整性，在使用中继续提供对环境危害的保护。

How the Test Simulates Real-World Reeling Cable Life Cycles | 测试如何模拟真实世界卷筒电缆生命周期

Correlation Between Test Cycles and Operational Life | 测试周期与操作寿命之间的相关性

The relationship between laboratory test cycles and actual service life depends on multiple operational variables including daily usage frequency, bending radius during deployment, operational speed, environmental conditions, and maintenance practices. For typical monospiral drum applications in mining operations, equipment may complete between 50 to 200 winding and unwinding cycles per shift. Operating two or three shifts daily results in 100 to 600 operational cycles per day. Under these conditions, a cable that successfully completes 30,000 test cycles demonstrates an expected minimum service life ranging from 50 to 300 days of continuous operation.

实验室测试周期与实际使用寿命之间的关系取决于多个操作变量，包括每日使用频率、部署期间的弯曲半径、操作速度、环境条件和维护实践。对于采矿作业中典型的单螺旋卷筒应用，设备可能每班完成50到200次收卷和放卷循环。每天运行两班或三班导致每天100到600个操作周期。在这些条件下，成功完成30,000个测试周期的电缆表现出50到300天连续操作的预期最低使用寿命。

Stress Acceleration Factors | 应力加速因素

The two-pulley flexing test incorporates several acceleration factors that make the test more severe than typical operating conditions, providing a conservative safety margin for cable performance predictions. The continuous, uninterrupted cycling at constant speed eliminates rest periods that would occur during normal operation when equipment is idle. The applied weights create consistent tension throughout testing, whereas real-world tension may vary with cable position and equipment movement. The standardized pulley diameter establishes a minimum bend radius that may be tighter than some operational installations. These conservative test parameters ensure that cables passing the flexing test will perform reliably under a wide range of actual deployment conditions.

双滑轮挠曲测试包含几个加速因素，使测试比典型操作条件更严格，为电缆性能预测提供保守的安全裕度。以恒定速度连续不间断循环消除了设备空闲时正常操作期间发生的休息时间。施加的重量在整个测试期间产生一致的张力，而真实世界的张力可能随电缆位置和设备移动而变化。标准化的滑轮直径建立了最小弯曲半径，可能比某些操作安装更紧。这些保守的测试参数确保通过挠曲测试的电缆在广泛的实际部署条件下可靠地执行。

Failure Mode Identification | 失效模式识别

The continuous electrical monitoring during flexing tests provides valuable diagnostic information about how and why cables fail under repeated mechanical stress. Common failure modes identified through two-pulley testing include conductor strand breakage due to work hardening, insulation cracking from repeated compression and elongation cycles, and sheath abrasion from contact with pulley surfaces. Understanding these failure mechanisms enables cable designers to optimize conductor stranding patterns, select more flexible insulation compounds, and improve sheath material formulations to enhance overall flex life performance.

挠曲测试期间的连续电气监控提供了有关电缆在重复机械应力下如何以及为什么失效的有价值的诊断信息。通过双滑轮测试识别的常见失效模式包括由于加工硬化导致的导体股线断裂、由于重复压缩和伸长周期导致的绝缘开裂以及由于与滑轮表面接触导致的护套磨损。理解这些失效机制使电缆设计师能够优化导体绞合模式、选择更柔性的绝缘化合物并改进护套材料配方以增强整体挠曲寿命性能。

Application to (N)TSCGEWÖU Mining Cables | 应用于(N)TSCGEWÖU采矿电缆

Specialized Testing Considerations | 专业测试考虑因素

The (N)TSCGEWÖU cable designation represents medium-voltage flexible power cables specifically engineered for demanding mining applications including monospiral drum operations and trailing cable systems. These cables incorporate specialized construction features including Class 5 finely stranded tinned copper conductors for enhanced flexibility, rubber insulation compounds designed for mechanical resilience, and heavy-duty elastomer outer sheaths that resist abrasion, oil, and environmental degradation. While standard BS EN 50396 flexing tests apply to lower voltage cables with smaller conductors, the same fundamental test methodology can be adapted with modified parameters for medium-voltage mining cables.

(N)TSCGEWÖU电缆名称代表中压柔性电力电缆，专为要求严格的采矿应用而设计，包括单螺旋卷筒操作和拖曳电缆系统。这些电缆包含专门的结构特征，包括用于增强柔性的5类细绞镀锡铜导体、为机械弹性设计的橡胶绝缘化合物以及抵抗磨损、油和环境降解的重型弹性体外护套。虽然标准BS EN 50396挠曲测试适用于具有较小导体的低压电缆，但可以使用修改的参数将相同的基本测试方法应用于中压采矿电缆。

Enhanced Performance Requirements | 增强的性能要求

Mining cable manufacturers often subject their products to more stringent flexing test protocols than the minimum 30,000-cycle standard. Advanced cable designs intended for critical mining applications may undergo testing to 1 million cycles or more, with some specialty manufacturers achieving verified performance exceeding 10 million flex cycles. These extended cycle tests provide higher confidence in long-term reliability for applications where cable failure could result in significant safety hazards or costly production interruptions. The additional testing also validates design improvements such as optimized conductor configurations, advanced insulation formulations, and reinforced sheath constructions.

采矿电缆制造商通常使其产品接受比最低30,000周期标准更严格的挠曲测试协议。用于关键采矿应用的高级电缆设计可能经历100万次循环或更多的测试，一些专业制造商实现了超过1000万次挠曲循环的经过验证的性能。这些延长的周期测试为长期可靠性提供了更高的信心，用于电缆故障可能导致重大安全隐患或昂贵的生产中断的应用。额外的测试还验证了设计改进，例如优化的导体配置、先进的绝缘配方和增强的护套结构。

Comparison with Other Flexing Test Methods | 与其他挠曲测试方法的比较

Static Flexibility Testing | 静态柔性测试

Static flexibility tests, as defined in IEC 60245-2 Clause 3.2, evaluate a cable’s ability to be bent into a U-shape configuration without cracking or damage. In this test, a 3-meter cable sample is clamped at both ends, and one end is moved to form the cable into a standard U-shape. While this test confirms basic installation flexibility, it does not simulate the repetitive flexing stress that reeling cables experience during operational use. Static flexibility testing is primarily useful for validating that cables can be manipulated during installation without immediate damage, but it provides no data about long-term flex endurance.

静态柔性测试，如IEC 60245-2第3.2条所定义，评估电缆在不开裂或损坏的情况下弯曲成U形配置的能力。在这个测试中，一个3米长的电缆样品在两端被夹紧，一端被移动以将电缆形成标准的U形。虽然这个测试确认了基本的安装柔性，但它不模拟卷筒电缆在操作使用期间经历的重复挠曲应力。静态柔性测试主要用于验证电缆在安装期间可以被操纵而不会立即损坏，但它不提供有关长期挠曲耐久性的数据。

Three-Pulley Flexing Test | 三滑轮挠曲测试

Some testing protocols employ a three-pulley configuration instead of the two-pulley system. The three-pulley test typically operates at a slower speed of 0.1 m/s and may use different weight loading configurations. While both test methods subject cables to repetitive flexing stress, the two-pulley test more accurately simulates the bending patterns experienced by cables in typical drum reeling applications. The choice between two-pulley and three-pulley testing depends on the specific application requirements and the cable construction being evaluated.

一些测试协议采用三滑轮配置而不是双滑轮系统。三滑轮测试通常以0.1米/秒的较慢速度运行，并可能使用不同的重量负载配置。虽然两种测试方法都使电缆承受重复的挠曲应力，但双滑轮测试更准确地模拟了典型卷筒收卷应用中电缆经历的弯曲模式。双滑轮和三滑轮测试之间的选择取决于具体的应用要求和正在评估的电缆结构。

Torsional Twist Testing | 扭转扭曲测试

Torsional twist testing evaluates cable performance under rotational stress rather than pure bending stress. This test subjects cables to repeated 360-degree or even 540-degree twisting motions in both clockwise and counterclockwise directions while monitoring electrical continuity. Torsional testing is particularly relevant for cables used in robotic applications or rotating equipment where twisting forces dominate. However, for reeling cable applications where the primary stress mechanism is bending rather than twisting, the two-pulley flexing test provides more relevant performance data.

扭转扭曲测试评估电缆在旋转应力下的性能，而不是纯弯曲应力。这个测试使电缆在顺时针和逆时针方向重复360度甚至540度的扭曲运动，同时监控电气连续性。扭转测试特别适用于用于机器人应用或扭曲力占主导地位的旋转设备的电缆。然而，对于主要应力机制是弯曲而不是扭曲的卷筒电缆应用，双滑轮挠曲测试提供了更相关的性能数据。