如何使用Kellem电缆夹正确对垂直悬挂电缆((N)SHTÖU)进行应力消除
How to Properly Strain-Relieve Vertical Suspension Cables ((N)SHTÖU) Using Kellem Grips
如何使用Kellem电缆夹正确对垂直悬挂电缆((N)SHTÖU)进行应力消除
1. Introduction to (N)SHTÖU Cables — (N)SHTÖU电缆简介
The (N)SHTÖU cable is a flexible rubber-sheathed cable specifically engineered for reeling and festoon applications in cranes, hoists, and other material handling equipment. According to DIN VDE 0250-814 and harmonized standard HD 22.10 S2, these cables feature exceptional mechanical resilience and are rated for continuous flexing operations under demanding industrial conditions. (N)SHTÖU电缆是专为起重机、提升机及其他物料搬运设备的卷筒和悬链系统设计的柔性橡胶护套电缆。根据DIN VDE 0250-814及协调标准HD 22.10 S2，这类电缆具有出色的机械弹性，适用于严苛工业环境下的连续弯曲操作。
| Standard 执行标准 | DIN VDE 0250-814 / HD 22.10 S2 |
| Rated Voltage 额定电压 | 450/750V (AC) / 600/1000V (DC) |
| Temperature Range 温度范围 | -25°C to +60°C (fixed) / -40°C to +60°C (flexible) |
| Conductor Material 导体材料 | Class 5 Fine-Stranded Copper per IEC 60228 |
| Sheath Material 护套材料 | Heavy-duty Polychloroprene (PCP) rubber compound |
| Minimum Bending Radius 最小弯曲半径 | 7.5 × overall diameter (dynamic use) |
2. Understanding Kellem Cable Grips — 认识Kellem电缆夹
Kellem grips (also known as cable pulling grips or Chinese finger grips) are woven wire mesh devices manufactured by Hubbell/Kellems that provide secure strain relief through a self-tightening mechanism. When tensile load is applied, the mesh contracts around the cable jacket, distributing stress evenly across a larger surface area and preventing localized damage to the conductor insulation. Kellem电缆夹（也称为电缆牵引夹或中国指套）是由Hubbell/Kellems制造的编织金属丝网装置，通过自锁机制提供可靠的应力消除。当施加拉力时，丝网收缩包裹在电缆护套上，将应力均匀分布在较大的表面积上，防止导体绝缘层局部损坏。
2.1 Kellem Grip Selection Criteria — Kellem夹选型标准
| Cable O.D. Range (mm) 电缆外径范围 | Grip Model Series 夹具型号系列 | Safe Working Load 安全工作负载 | Mesh Material 丝网材料 |
|---|---|---|---|
| 6.4 – 12.7 | 033-02-xxx | 227 kg (500 lbs) | Galvanized Steel |
| 12.7 – 19.1 | 033-03-xxx | 454 kg (1,000 lbs) | Galvanized Steel |
| 19.1 – 25.4 | 033-04-xxx | 680 kg (1,500 lbs) | Galvanized Steel |
| 25.4 – 38.1 | 033-05-xxx | 907 kg (2,000 lbs) | Galvanized / Stainless |
| 38.1 – 50.8 | 033-06-xxx | 1,134 kg (2,500 lbs) | Stainless Steel 316 |
3. Step-by-Step Installation Procedure — 分步安装流程
Determine the total suspended cable weight using the formula: W = L × m, where L is the vertical length (m) and m is the cable mass per unit length (kg/m). For (N)SHTÖU 4G2.5, typical mass is approximately 0.28 kg/m. Apply a minimum safety factor of 5:1 per ASME B30.20 standards for below-the-hook lifting devices. 使用公式W = L × m计算悬挂电缆总重量，其中L为垂直长度（米），m为单位长度电缆质量（千克/米）。对于(N)SHTÖU 4G2.5，典型质量约为0.28千克/米。根据ASME B30.20吊钩下起重装置标准，采用最小5:1的安全系数。
Measure the cable outer diameter precisely using calibrated calipers. The grip’s working range should encompass the measured O.D. with 10-15% margin. An undersized grip will not develop full holding capacity; an oversized grip may slip under load. 使用校准卡尺精确测量电缆外径。夹具的工作范围应涵盖测量的外径并留有10-15%的余量。过小的夹具无法发挥全部夹持能力；过大的夹具可能在负载下滑脱。
Clean the cable jacket with isopropyl alcohol to remove oils, dust, and contaminants that could reduce friction. Inspect for jacket damage, cuts, or abrasions that might compromise grip integrity. Do not install grips over damaged sections. 用异丙醇清洁电缆护套，去除可能降低摩擦力的油污、灰尘和杂质。检查护套是否有损坏、切口或磨损，这些都可能影响夹持完整性。不要在损坏部位安装夹具。
Expand the mesh by pushing toward the closed end (against the weave direction). Slide the cable through until adequate mesh length covers the jacket—minimum 150mm engagement for vertical suspension applications per IEEE 1185 recommendations. Release the mesh to allow it to contract onto the cable. 通过向封闭端推压（逆编织方向）展开丝网。将电缆穿过，直到足够长度的丝网覆盖护套——根据IEEE 1185建议，垂直悬挂应用的最小接合长度为150毫米。释放丝网使其收缩到电缆上。
Connect the grip’s eye or bail to the support hardware using appropriately rated shackles or quick-links. Ensure all hardware meets or exceeds the calculated working load limit. Verify that the load path is direct and does not introduce side-loading on the grip eye. 使用额定负载合适的卸扣或快速连接件将夹具的吊环或吊耳连接到支撑硬件。确保所有硬件达到或超过计算的工作负载极限。验证负载路径是否直接，不会对夹具吊环产生侧向载荷。
Perform a visual inspection and apply a proof load (typically 1.25× working load) before placing into service. Document the installation including grip model, cable type, date, and inspector credentials per ISO 9001 quality management requirements. 在投入使用前进行目视检查并施加验证载荷（通常为工作载荷的1.25倍）。根据ISO 9001质量管理要求记录安装信息，包括夹具型号、电缆类型、日期和检查人员资质。
4. Load Calculation Reference — 负载计算参考
| Cable Type 电缆型号 | Cross-Section 截面 | O.D. (mm) 外径 | Mass (kg/m) 质量 | Max. Vertical Run* 最大垂直长度* |
|---|---|---|---|---|
| (N)SHTÖU | 3G1.5 | 10.8 | 0.21 | 216 m |
| (N)SHTÖU | 4G2.5 | 13.2 | 0.28 | 324 m |
| (N)SHTÖU | 4G4 | 14.8 | 0.38 | 239 m |
| (N)SHTÖU | 4G6 | 16.5 | 0.52 | 175 m |
| (N)SHTÖU | 4G10 | 19.8 | 0.78 | 174 m |
| (N)SHTÖU | 4G16 | 23.5 | 1.15 | 158 m |
*Based on 033-series grip with 5:1 safety factor. Actual limits depend on specific grip model selected. 基于033系列夹具，5:1安全系数。实际限值取决于所选具体夹具型号。
5. Common Installation Errors — 常见安装错误
| Error Type 错误类型 | Consequence 后果 | Prevention 预防措施 |
|---|---|---|
| Insufficient mesh engagement 丝网接合不足 | Reduced holding capacity, potential slippage 夹持力降低，可能滑脱 | Ensure minimum 150mm coverage 确保最小150mm覆盖 |
| Oversized grip selection 选择过大的夹具 | Grip cannot fully contract, load capacity compromised 夹具无法完全收缩，负载能力受损 | Verify O.D. falls within grip’s specified range 验证外径在夹具规定范围内 |
| Side-loading the eye 吊环侧向受力 | Premature eye failure, unexpected release 吊环过早失效，意外脱落 | Ensure axial alignment of load path 确保负载路径轴向对齐 |
| Installation over damaged jacket 在损坏护套上安装 | Jacket tear propagation under load 负载下护套撕裂扩展 | Inspect and reject damaged cables 检查并拒绝使用损坏电缆 |
6. Applicable Standards Summary — 适用标准汇总
| Standard 标准 | Scope 范围 |
|---|---|
| DIN VDE 0250-814 | Rubber-insulated cables for reeling purposes 卷筒用橡胶绝缘电缆 |
| HD 22.10 S2 | Harmonized standard for lift and crane cables 电梯和起重机电缆协调标准 |
| IEC 60228 | Conductor specifications for cables 电缆导体规范 |
| IEEE 1185 | Cable installation in generating stations 发电站电缆安装 |
| ASME B30.20 | Below-the-hook lifting devices 吊钩下起重装置 |
| NEC Article 250 | Grounding and bonding requirements 接地与搭接要求 |
References & External Resources 参考文献与外部资源
- Hubbell Incorporated. “Kellems Cable Support Grips – Engineering Data.” hubbell.com/kellems
- DIN Deutsches Institut für Normung. “DIN VDE 0250-814:2022 – Cables for Reeling Purposes.” din.de
- International Electrotechnical Commission. “IEC 60228:2023 – Conductors of Insulated Cables.” iec.ch
- IEEE Standards Association. “IEEE 1185-2019 – Recommended Practice for Cable Installation.” standards.ieee.org
- ASME. “B30.20-2021 – Below-the-Hook Lifting Devices.” asme.org
- NFPA. “National Electrical Code (NEC) 2023 – Article 250.” nfpa.org/nec
安徽飞纯特种电缆有限公司
