Detailed Description
Control vs Power — Two Cables, One Reel System
Most reeling systems use two cables: a power cable for the motor, and a control cable for auxiliary signals. Separating them makes engineering sense — power and signal have different requirements:
| Reeling Power Cable | Reeling Control Cable | |
|---|---|---|
| Core cross-section | 1.5–400 mm² | 0.5–2.5 mm² |
| Core count | 3–5 | 2–36 |
| Weight | Heavy (2–40 kg/m) | Light (0.1–1.0 kg/m) |
| Reel type | Motorized drum | Spring reel or light motorized |
| Tensile reinforcement | Steel wire (required) | Kevlar (optional, lightweight) |
| Primary stress | Cable weight + winding tension | Spring retraction + repeated coiling |
The control cable does not carry significant power — it carries 24 V DC PLC signals, 230 V AC relay coils, and milliamp sensor loops. The engineering focus is on signal integrity, core identification, and spring reel compatibility — not on tensile strength or current capacity.
Anti-Twist — The Spring Reel Requirement
A spring-driven control cable reel retracts under constant spring tension. If the cable develops coiling memory (a permanent spiral shape from being wound on the drum), the retraction becomes uneven — the cable bunches, tangles, or fails to retract fully.
Short-lay anti-twist stranding prevents this: the cores are twisted with a deliberately short lay length in alternating directions per layer. This cancels the internal torsional stress that causes coiling memory. The cable lies flat on the drum and retracts smoothly — every time.
Kevlar Tensile Element — When to Add It
Standard reeling control cable relies on the copper conductors for tensile strength during retraction. For short reels (< 15 m) with lightweight cable, this is adequate. For longer reels or heavier cable:
- Kevlar center core: A non-conductive aramid fiber strand in the cable center carries tensile load during retraction — the copper conductors carry zero tension
- Weight penalty: Negligible — Kevlar is 80% lighter than steel wire of equivalent strength
- Electrical advantage: Kevlar is non-conductive — no risk of the tensile element shorting to a conductor if insulation is damaged
Why Choose Yichi Cable Reeling Control?
- Spring reel optimized: Short-lay anti-twist stranding + lightweight construction — designed for spring retraction, not just adapted from fixed control cable
- Kevlar option: Add tensile support without the weight or conductivity penalty of steel
- Full color/number choice: DIN 47100 color coding or VDE 0293 numbering — your standard, your choice
- Compact OD: Thin-wall PP insulation + compact stranding = smaller OD → more cable on the same reel