Detailed Description
Steel Wire Core — Two Functions in One
The central conductor in this cable is a galvanized steel wire rope. It serves two functions:
- Mechanical: Carries the tensile load from the cable's own weight as it unwinds from the motorized drum — the copper conductors experience zero tension during reeling
- Electrical: Serves as the equipment ground (PE) conductor — eliminating the need for a separate ground core and reducing the overall cable OD
When to Use Steel Wire vs Flat
| Overhead Crane Cable with Steel Wire | Overhead Crane Flat Cable | |
|---|---|---|
| Application | Motorized drum reeling | Festoon loop system |
| Crane type | Hoist, trolley, bridge drive power | Trolley traverse festoon |
| Steel messenger | Central — carries tension + ground | Edge — supports cable horizontally |
| Strength | Withstands vertical cable weight | Supports horizontal loop spans |
| Motion | Winding/unwinding on drum | Expanding/contracting festoon loops |
Steel wire round cable is for vertical reeling — the hoist moving up and down. Flat cable is for horizontal festoon — the trolley moving left and right along the bridge. Most overhead cranes use both: steel wire cable on the hoist drum, flat cable on the trolley festoon.
Construction Summary
| Element | Specification |
|---|---|
| Power conductors | Bare copper, IEC 60228 Class 5 or Class 6; 4-95 mm² |
| Control conductors (optional) | 0.75-2.5 mm²; 2-12 cores |
| Core insulation | EPR - compression-resistant, high dielectric |
| Core stranding | Concentric around the central steel wire core |
| Steel wire core | Galvanized, 1 770 N/mm² - central; carries tension and serves as ground |
| Steel core working load | 10-30 kN (application-specific) |
| Inner sheath (optional) | CR or NBR rubber |
| Outer jacket | CR neoprene (black, standard heavy-duty) or PUR TMPU (halogen-free, outdoor/heavy-duty) |
Electrical and Reeling Duty
- Rated voltage 0.6/1 kV, test voltage 3 500 V AC for 5 minutes
- Temperature range -25 °C to +70 °C with the CR jacket, or -40 °C to +80 °C with the PUR jacket
- Minimum D/d 10:1, with 12:1 recommended
- More than 100 000 reeling cycles achieved at 12:1 D/d
- Flame retardant to IEC 60332-1-2
- CE and RoHS compliant
Applications
- EOT crane hoist motor power - motorized drum cable for main and auxiliary hoist
- Trolley traverse drive - motorized drum cable for trolley motor power
- Bridge drive motor - long-travel drum cable for crane bridge drive
- Crane auxiliary power - grab, magnet, vacuum lifter power supply reeling
- Workshop and warehouse overhead crane - general motorized drum reeling