Earth Fault Protection: The Need for 3.3/3.3kV Rating on German Flat PROTOLON Cables
Non-earthed IT (Isolated Terra) power systems represent a deliberate design choice in heavy industrial applications—particularly in port machinery, mining equipment, and large festoon crane systems—where operational continuity is paramount. Unlike the grounded (TN or TT) systems standard in most commercial buildings, IT systems are engineered to tolerate single-phase earth faults without automatic shutdown.
非接地IT(隔离接地)电源系统代表了重工业应用中的一个刻意设计选择——特别是在港口机械、采矿设备和大型自动供电起重机系统中——其中运营连续性至关重要。与大多数商业建筑中标准的接地(TN或TT)系统不同,IT系统经过设计,可以在单相接地故障时继续运行而不需要自动断电。



![What is the Maximum Conductor Operating Temperature Allowed for VDE Cables Insulated with EPR (90°C) vs. Older Rubber Types? 4 The maximum conductor operating temperature is a critical parameter that determines a cable's current-carrying capacity, service life, and application suitability. For VDE-certified cables, EPR (Ethylene Propylene Rubber) insulation permits a continuous conductor operating temperature of 90°C, representing a significant advancement over older rubber insulation technologies which were typically limited to 60°C–70°C.[1][2] 最高导体工作温度是决定电缆载流量、使用寿命和应用适用性的关键参数。对于VDE认证电缆,EPR(乙丙橡胶)绝缘允许90°C的连续导体工作温度,相比传统橡胶绝缘(60°C–70°C)有显著提升。](https://feichuncables.com/blog/wp-content/uploads/image-574.avif)

