STS crane power cable

The nominal outer diameter of NSHTÖU-J 4G50 (four 50 mm² power conductors plus one integrated green/yellow earth conductor, five total) is approximately 42.0–48.0 mm, whereas the equivalent 4×50 configuration (four 50 mm² power conductors only, four total, no dedicated earth conductor) is nominally approximately 38.5–44.5 mm, representing an outer diameter differential of roughly 3.5–4.0 mm in nominal specification ranges. This diameter increase in the 4G50 configuration reflects the spatial and mechanical requirements necessary to integrate the additional green/yellow earth conductor into the cable cross-section while maintaining proper insulation distances between all conductors, adequate mechanical spacing to distribute stress during high-speed reeling operations, and structural integrity under the extreme tensile loads encountered in port cranes, mining draglines, and industrial lifting applications. The 4G50 configuration typically exhibits copper content of approximately 1,920 kg/km (including the earth conductor), while 4×50 exhibits approximately 1,680–1,750 kg/km (earth conductor copper excluded), and total cable weight differs by approximately 300–400 kg/km, reflecting the substantial additional material required to safely integrate the fifth conductor. Both configurations comply with DIN VDE 0250-814 requirements for heavy-duty rubber reeling cables, but they serve different grounding architecture philosophies: the 4G50 is integrated-earth design (ground circuit built into the cable cross-section), while the 4×50 typically requires external earth/ground conductors or relies on external armor or cable tray grounding, making it more suitable for installations where ground paths can be established through equipment frames or external conductors.