Introduction 介绍

When installing power cables in vertical shafts, elevator shafts, or mining applications, proper mechanical support is essential to prevent cable degradation and ensure long-term reliability. Sheath creepage, the phenomenon where cable outer sheaths slide or migrate downward under gravitational stress, represents a critical failure mechanism that can compromise cable integrity and system safety. This technical guide examines the VDE standards and international best practices for clamping distances when installing (N)TSCGEWÖU cables and similar heavy-duty mining cables in vertical configurations.

在垂直竖井、电梯井或采矿应用中安装电力电缆时，正确的机械支撑对于防止电缆退化和确保长期可靠性至关重要。护套蠕变是指电缆外护套在重力作用下向下滑动或迁移的现象，这是一种关键的失效机制，可能会损害电缆完整性和系统安全。本技术指南探讨了在垂直配置中安装(N)TSCGEWÖU电缆和类似重型采矿电缆时的VDE标准和国际最佳实践的夹紧距离。

Understanding (N)TSCGEWÖU Cables 了解(N)TSCGEWÖU电缆

(N)TSCGEWÖU cables are heavy-duty flexible mining and reeling cables manufactured according to DIN VDE 0250 standards. These cables feature tough rubber sheathing designed for extreme mechanical stress, abrasion resistance, and submersible applications up to 100 meters depth. The designation indicates specific construction characteristics:

(N)TSCGEWÖU电缆是根据DIN VDE 0250标准制造的重型柔性采矿和卷筒电缆。这些电缆具有坚韧的橡胶护套，专为极端机械应力、耐磨损和100米深度的潜水应用而设计。

VDE Standards for Vertical Cable Installation VDE垂直电缆安装标准

DIN VDE 0298 Series: Cable Application Guidelines DIN VDE 0298系列：电缆应用指南

The DIN VDE 0298 standard series provides comprehensive guidelines for cable application in power installations. Specifically, DIN VDE 0298-3 addresses the use of non-harmonized cables and includes provisions for mechanical installation requirements including bending radii and support methods. While VDE standards primarily focus on electrical safety parameters such as clearance and creepage distances for insulation coordination, the mechanical support requirements for vertical installations draw from both German national standards and international practices.

DIN VDE 0298标准系列为电力装置中的电缆应用提供了全面的指南。具体而言，DIN VDE 0298-3涉及非统一电缆的使用，并包括机械安装要求的规定，包括弯曲半径和支撑方法。

Electrical vs. Mechanical Support Requirements 电气与机械支撑要求

It is important to distinguish between two types of spacing requirements in cable standards. VDE standards such as DIN VDE 0110-1 (based on IEC 60664-1) primarily address clearance and creepage distances for electrical insulation coordination. These measurements ensure adequate spacing between conductive parts to prevent electrical breakdown and arcing. According to industry technical documentation, creepage distance represents the shortest path along an insulating surface between conductors, while clearance refers to the direct air gap distance.

重要的是要区分电缆标准中的两种间距要求。VDE标准如DIN VDE 0110-1（基于IEC 60664-1）主要涉及电气绝缘协调的间隙和爬电距离。这些测量确保导电部件之间有足够的间距以防止电击穿和电弧。

However, mechanical support spacing for vertical installations serves a different purpose: preventing cable damage from gravitational stress, sheath slippage, and strain concentration at termination points. These mechanical requirements are governed by installation standards rather than purely electrical safety standards.

International Standards for Vertical Cable Support 垂直电缆支撑的国际标准

NEC 300.19: Supporting Conductors in Vertical Raceways NEC 300.19：垂直线槽中的导体支撑

The National Electrical Code (NEC) Article 300.19, published by the National Fire Protection Association (NFPA 70), provides the most widely recognized technical framework for supporting conductors in vertical installations. According to NEC 300.19(A), conductors in vertical raceways must be supported when the vertical rise exceeds specified values based on conductor size. One cable support must be provided at the top of the vertical raceway or as close to the top as practical, with intermediate supports installed to limit unsupported conductor lengths.

由美国国家消防协会（NFPA 70）发布的《国家电气规范》（NEC）第300.19条为垂直安装中的导体支撑提供了最广泛认可的技术框架。

Note 注意: Data derived from NFPA 70 NEC Table 300.19(A). For steel wire armored cables, special clamping methods must be employed that clamp the armor rather than the insulation. A safety device should be installed at the lower end to prevent slippage in case of support failure.

注意: 数据来源于NFPA 70 NEC表300.19(A)。对于钢丝铠装电缆，必须采用夹紧铠装而非绝缘层的特殊夹紧方法。应在下端安装安全装置以防止支撑失效时的滑移。

Practical Recommendations for (N)TSCGEWÖU Cable Installation (N)TSCGEWÖU电缆安装的实用建议

Clamping Distance Recommendations 夹紧距离建议

For heavy-duty mining cables such as (N)TSCGEWÖU installed in vertical shafts, conservative support spacing is recommended due to the cable’s significant weight and flexibility. Based on international standards and manufacturer recommendations, the following guidelines should be observed:

对于安装在垂直竖井中的(N)TSCGEWÖU等重型采矿电缆，由于电缆重量大且柔韧性高，建议采用保守的支撑间距。

Support Method Selection 支撑方法选择

According to NEC 300.19(C), several approved methods exist for supporting cables in vertical installations. For rubber-sheathed mining cables, the following methods are recommended in order of preference:

根据NEC 300.19(C)，垂直安装中支撑电缆有几种认可的方法。对于橡胶护套采矿电缆，按优先顺序推荐以下方法：

Clamping Devices with Insulating Wedges 带绝缘楔块的夹紧装置: The most common method employs insulating wedge plugs inserted at raceway terminations. These devices distribute clamping pressure uniformly around the cable circumference without damaging the outer sheath. For (N)TSCGEWÖU cables, multiple-segment wedge designs are preferred over single-piece plugs to accommodate the softer insulation compounds used in mining applications.

具有绝缘楔块的夹紧装置: 最常见的方法是在线槽终端插入绝缘楔形塞。这些装置在电缆周围均匀分布夹紧压力，而不会损坏外护套。

Junction Box Deflection Method 接线盒偏转方法: Cables can be supported by deflecting them at least ninety degrees within junction boxes and carrying them horizontally for a distance not less than twice the cable diameter. When this method is employed, support spacing must be reduced to twenty percent of the standard intervals specified in Table 300.19(A).

Steel Wire Armor Specific Supports 钢丝铠装专用支撑: Although (N)TSCGEWÖU cables do not typically incorporate steel wire armor, similar heavy-duty cables with metallic reinforcement require specialized support clamps that grip the armor layer. These installations must include fail-safe devices at the lower terminus to prevent catastrophic failure if primary supports slip.

Prevention of Sheath Creepage 护套蠕变的预防

Understanding Sheath Creepage Mechanisms 了解护套蠕变机制

Sheath creepage in vertical cable installations occurs when the outer protective layer migrates downward relative to the internal conductors due to insufficient mechanical support. This phenomenon is particularly problematic in rubber-sheathed cables where the sheath material exhibits viscoelastic properties under sustained stress. Over time, gravitational forces can cause the sheath to slide, potentially exposing underlying insulation or creating stress concentrations at support points.

垂直电缆安装中的护套蠕变发生在外部保护层由于机械支撑不足而相对于内部导体向下迁移时。这种现象在橡胶护套电缆中尤其成问题，因为护套材料在持续应力下表现出粘弹性特性。

Design Strategies for Creepage Prevention 蠕变预防的设计策略

Effective prevention of sheath creepage requires a comprehensive approach addressing both support design and installation methodology. Primary support clamps should distribute clamping force over a sufficient length of cable to prevent point loading that could initiate sheath movement. Industry experience suggests that support clamps engaging at least 150-200mm of cable length provide optimal stress distribution for mining-grade cables.

有效预防护套蠕变需要综合考虑支撑设计和安装方法。主要支撑夹应在足够长度的电缆上分配夹紧力，以防止可能引发护套移动的点载荷。

Temperature cycling in shaft environments can exacerbate creepage tendencies by causing cyclic expansion and contraction of sheath materials. In applications where temperature variations exceed thirty degrees Celsius, consideration should be given to reducing standard support intervals by twenty to thirty percent. The polychloroprene (chloroprene rubber) outer sheath used in (N)TSCGEWÖU cables provides good resistance to creepage compared to standard PVC, but proper mechanical support remains essential.

竖井环境中的温度循环可能通过引起护套材料的循环膨胀和收缩而加剧蠕变倾向。在温度变化超过30摄氏度的应用中，应考虑将标准支撑间隔减少20%至30%。

Installation Best Practices 安装最佳实践

Pre-Installation Planning 安装前规划

Successful vertical cable installation begins with thorough planning that accounts for shaft geometry, cable weight, environmental conditions, and access limitations. Cable weight calculations must consider both the linear weight per meter and the cumulative weight at each support point. For (N)TSCGEWÖU cables in common cross-sections, linear weights typically range from three to fifteen kilograms per meter depending on conductor size and number of cores.

成功的垂直电缆安装始于充分的规划，考虑竖井几何形状、电缆重量、环境条件和通道限制。电缆重量计算必须考虑每米的线性重量和每个支撑点的累积重量。

Pulling and Installation Techniques 拉动和安装技术

Vertical cable pulling requires specialized techniques to prevent damage during installation. When pulling cables upward in vertical shafts, synchronized cable pushers positioned at multiple levels can reduce tensile stress compared to single-point pulling from the top. Breaking mechanisms must be installed to prevent free-fall in the event of pulling wire failure, as gravitational acceleration can quickly exceed the cable’s structural capacity. Professional installation companies with experience in hydro power, mining, or high-rise applications should be consulted for complex vertical installations exceeding fifty meters.

垂直电缆拉动需要专门的技术以防止安装过程中的损坏。在垂直竖井中向上拉电缆时，位于多个水平的同步电缆推进器可以减少与从顶部单点拉动相比的拉伸应力。

Snaking and Fixation 蛇形布置和固定

Once cables are positioned in vertical shafts, proper snaking (controlled slack routing) prevents excessive strain at support points while accommodating thermal expansion and contraction. The cable route should follow a gentle sinusoidal pattern between support clamps, with the amplitude of each curve proportional to the support spacing. Care must be taken to avoid creating closed loops of ferromagnetic steel in support structures, as these can induce heating through electromagnetic coupling in power cables.

一旦电缆定位在垂直竖井中，适当的蛇形布置（受控松弛路由）可防止支撑点处的过度应变，同时适应热膨胀和收缩。

Compliance and Quality Assurance 合规性和质量保证

Installations should be documented with detailed support spacing measurements, clamp torque specifications, and photographic evidence of proper installation. Regular inspection intervals should be established to monitor for signs of sheath migration, support loosening, or environmental degradation. Particular attention should be paid to the top support point and first intermediate support, as these locations experience the highest sustained stress.

安装应记录详细的支撑间距测量、夹紧扭矩规格和适当安装的照片证据。应建立定期检查间隔以监测护套迁移、支撑松动或环境退化的迹象。

Quality cable materials conforming to DIN VDE 0250 specifications provide the foundation for reliable vertical installations. (N)TSCGEWÖU cables manufactured to these standards incorporate sheath compounds specifically formulated to resist creepage under sustained mechanical stress. However, no cable construction can compensate for inadequate mechanical support design.