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Filling rules - cables and hoses in energy chains

The key advantage of our energy chain systems is they can safely accommodate a wide variety of forms of data cables and energy suppliers in one system. You have options of how to separate the different medias and maintain minimum distances between bus and motor cables. You can mix pneumatics, electrical cables and hydraulics in the same compartments. In addition to the quality of the cables used, the arrangement of each cable within the energy chain and the space allowed are important for the system's service life. Various separation options allow energy chains to be adapted to the specific requirements of each application. 

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Energy chain filling rules


Maximum cable or hose diameter

The maximum cable and/or hose diameter equals the inner height of the selected energy chains and energy tubes plus minimum clearance. This minimum clearance is 10% for electrical round cables and 20% for hydraulic hoses, for example. An energy chain is ideally filled if minimum lateral clearance to the next cable or hose has been factored in. Depending on the nature of the cables, the dynamics, and the expected service life, more clearance may be required. In specific cases, filling may be designed with less clearance. Please contact us.
Electrical cables require at least 10% clearance space all around, and hydraulic hoses require 20%.
The maximum cable/hose diameter is specified for each energy chain series on the relevant product page and in the relevant catalogue chapter.

Instructions for energy chain interior separation

Energy chain filling rules
Cables and hoses with very different diameters should be laid separately. Separators are used for this. Cables and hoses must under no circumstances have the opportunity to tangle. Therefore, the clearance height of a compartment with several similar cables or hoses next to one another must not be more than one and a half times the cable/hose diameter.
The cable or hose weight should be symmetrically distributed along the width of the energy chain. Cables and hoses with different outer jacket materials must not be allowed to stick together. They may need to be laid separately.

Filling rules

The cables and hoses must be laid so that they can move freely at all times and so that no tensile force is exerted on the energy chain at the radius. For high-speed applications and high numbers of load cycles, cables or hoses must not be laid on top of each other without horizontal separation. The standard values for this are: travel speed over 0.5m/s and load cycles over 10,000 p.a. igus interior separation offers a safe solution for such cases.
Energy chain filling rules

Filling rule 1: d1 + d2 > 1.2 x hi

If d1 + d2 > 1.2 x inner height, no separation between the two cables/hoses is necessary. Two cables/hoses should never be left unguided on top of one another or be allowed to become tangled.
Energy chain filling rules

Filling rule 1: d1 + d2 ≤ 1.2 x hi

If d1 + d2 ≤ 1.2 x inner height, a vertical separator or a horizontal shelf must be used to reduce the inner height. This prevents d1 and d2 from tangling.
Energy chain filling rules

Clearance space

Illustration showing the necessary clearance space around round electrical cables. For other cable types in %: electrical flat cables 10%, pneumatic hoses 5-10%, hydraulic hoses 20%, and media hoses 15-20%
Energy chain filling rules

Bend radius R

Your energy chain's bend radius depends on the thickest or stiffest cable or hose in your filling. The bend radii should be adjusted to the recommendations of the cable or hose manufacturer. Selecting a larger radius than the minimum will extend service life. The specification of minimum bend radii for cables and hoses refers to normal temperatures. Other bend radii may be recommended.

Filling rules | Round electrical cables

For electrical cables, the round cable is a safe, modular, cost-effective solution for energy chain systems.
Distribution rules

Installation and strain relief for round electrical cables

1) The cables must be laid straight, without twisting. Cables must not be uncoiled from the top of the spool. Our chainflex cables are immediately ready for placement directly into the e-chain®. They need not be disconnected or laid out before installation.
2) The cables must be laid in such a way that each individual cable can move freely in the longitudinal direction.
3) The cables must be able to move freely along the radius. This must be double-checked if the upper run has reached the greatest free length
4) igus interior separators are necessary if several cables and/or hoses with varying diameters are inserted. It is important to prevent cables and hoses from tangling.
5) Cables and hoses with different jacket materials must not be allowed to stick together. They may need to be separated. igus chainflex cables of all series can be combined.
6) Round electrical cables must have strain relief at both ends. In exceptional cases, cables may have strain relief at the energy chain's moving end only. A gap of 10-30 times the cable diameter between the end of the bend segment and the fixed point is recommended for most cables. chainflex cables can, on the other hand, have strain relief directly at the mounting bracket, as testing has confirmed.

Filling rules | Pneumatic hoses

In principle, the rules for round cables also apply to pneumatic hoses. After consultation, they can be laid together more closely than the 10% clearance rule allows. This requires double-sided strain relief. For pneumatic hoses made of rubber, we recommend that the 10% clearance rule be strictly followed because these hoses tend to stick to each other and to other cables and hoses.
Filling rules for pneumatic hoses

Filling rules | Flat cables

It is especially important for flat cables to move freely at the bend radius. Two adjacent flat cables should be kept apart with separators. If two flat cables are laid on top of one another, we strongly recommend horizontal interior separation. Flat and round cables should be laid separately in the energy chain. There should be strain relief at both ends. Flat cables are only recommended to a limited extent for use in energy chains.
Filling rules for flat cables

Filling rules | Hydraulic hoses

During planning, pay special attention to longitudinal and transverse expansion when the hoses are pressurised. We recommend energy chains with crossbars every link to distribute the force of the hoses over more crossbars. Sufficient room must be left (20% clearance). It is important for selected hoses to be sufficiently flexible (they must bend in the specified radius). The surface of the hoses must also be abrasion-resistant and able to glide. The igus interior separation elements minimise hose abrasion with their wide, smooth, rounded contact surfaces. Hoses with textile braiding are usually more flexible than those with steel wire braiding. Because lateral hydraulic hose movements within the energy chain can lead to increased abrasion in the hose material, hoses should be secured in position with vertical separators, and jamming must be avoided. Notch separators that snap into the crossbar, for example, keep the hoses firmly in place in the energy chain even if there is strong vibration and shocks.
Filling rules for hydraulic hoses

Strain relief

Hydraulic hoses are most often stretched lengthwise during operation. This must be taken into account when strain relief is applied. More hose length can be factored in or strain relief implemented. In some cases, one-sided strain relief on the moving end can be tolerated.


In almost all cases, the broad, smooth, rounded contact surfaces of all igus energy chains/energy tubes are sufficient to protect hydraulic hoses from abrasion. In extreme cases, the rollclip can be subsequently installed. In the crossbar, the hoses come into contact with a series of plastic cylinders which rotate with them. Extreme cases include particularly soft jacket materials, particularly small bend radii, and highly dynamic loads. Our experience shows that over 95% of all applications can be solved without rollclips.

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The terms "igus", "Apiro", "chainflex", "CFRIP", "conprotect", "CTD", "drylin", "dry-tech", "dryspin", "easy chain", "e-chain", "e-chain systems", "e-ketten", "e-kettensysteme", "e-skin", "e-spool", "flizz", "ibow", "igear", "iglidur", "igubal", "igutex", "kineKIT", "manus", "motion plastics", "pikchain", "readychain", "readycable", "ReBeL", "speedigus", "triflex", "robolink", "xirodur", and "xiros" are legally protected trademarks of the igus® GmbH/ Cologne in the Federal Republic of Germany and where applicable in some foreign countries.

igus® GmbH points out that it does not sell any products of the companies Allen Bradley, B&R, Baumüller, Beckhoff, Lahr, Control Techniques, Danaher Motion, ELAU, FAGOR, FANUC, Festo, Heidenhain, Jetter, Lenze, LinMot, LTi DRiVES, Mitsubishi, NUM,Parker, Bosch Rexroth, SEW, Siemens, Stöber and all other drive manufacturers mention on this website. The products offered by igus® are those of igus® GmbH