Cables for Reeling Drums and Motor-Driven Cable Reels
A reeling cable has to do something a carrier cable never does: wind onto a drum under tension, in layers, and then unwind. That introduces two loads that do not exist in a drag chain — constant tensile load from the drum, and torsion as the cable takes a set or as the drum pays out over a sheave. Reeling cable life is normally expressed against the D/d ratio, the drum diameter divided by cable diameter, because that ratio controls the bending strain in the outer layer.
A D/d of 15:1 is the usual minimum, 20:1 is the working recommendation, and 25:1 buys extended life. Below the minimum, jackets crack on the outside of the bend long before the conductors fail.
What decides the cable in this application
Four factors do most of the work. Getting these right narrows the choice to a small number of constructions, and each one appears in the specification table of the cable type you select.
D/d ratio sets the ceiling on reeling life
15:1 is the minimum, 20:1 recommended, 25:1 for extended life. The ratio is fixed by the drum the machine already has, so it is the first thing to establish before choosing a construction.
Winding in layers crushes the cable
Once the drum is three layers deep, the inner windings carry the weight of everything above them. Reeling cable is built with a jacket and core construction that resists this compression rather than deforming and thinning.
Tensile load is continuous, not intermittent
Unlike a festoon loop, a reeling drum keeps the cable under tension for the whole duty cycle. Steel wire or Kevlar reinforcement is what keeps that load out of the copper.
Torsion shows up on vertical reels and over sheaves
A cable paying out over a sheave or hanging on a vertical reel sees torsion as well as bending. Anti-torsion stranding prevents a spiral set from developing and keeps the cable tracking straight in the layer.
Cable types for reeling & drum machinery
14 constructions from the catalogue that suit this duty. Each links to its own page with the full specification table.
What we need to quote accurately
Send these six items and we can confirm a construction and price without a follow-up round. Both the contact page and every product page carry a form that accepts them, and you can attach a drawing or specification sheet directly.
- 1 Drum diameter and cable diameter So we can confirm the D/d ratio before anything else
- 2 Travel length and number of layers Metres of travel and how deep the drum winds
- 3 Tensile load Suspended weight at the free end, if the cable carries its own loop
- 4 Winding direction and sheaves Whether the cable pays out over a sheave or runs vertically
- 5 Conductor size and core count Power cores plus control and signal conductors
- 6 Environment Indoor or outdoor, temperature range, oil, salt spray, UV
Frequently asked questions
What D/d ratio should I specify for reeling cable?
15:1 is the minimum for reliable operation, 20:1 is what we recommend as a working ratio, and 25:1 gives extended life. Where the drum already exists, tell us its diameter and the cable diameter you need and we will confirm which band you are in.
How many layers can a reeling cable be wound in?
Multi-layer winding is normal on long travel machines, and the cable in the lower layers carries the compression of the layers above. Reeling cable is built for that load case; a cable intended only for festoon use is not, which is why the two duties are specified separately.
PVC, NBR or PUR jacket for a reeling drum?
PVC suits indoor machines with light duty. NBR (nitrile) is the common choice where oil mist and abrasion are present. PUR holds flexibility at low temperature and adds resistance to oil, coolant, UV and hydrolysis, which is what outdoor and washdown reels need.
Does a reeling cable need steel wire reinforcement?
It depends on whether the cable carries tensile load. On a motor-driven reel with a slack loop, the cable may not need it. On long vertical runs or where the loop weight hangs on the cable, reinforcement is what protects the conductors.
Need the cable confirmed against your machine?
Send the duty, the environment and the electrical data. Our engineering team will confirm the construction, the standards it meets, and the price — including custom builds where a catalogue type does not fit.