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Cable Handling & Routing Techniques
Basic Cable Handling and Routing Techniques
Improper handling of electronic cables may cause severe damage to the inside elements without showing any evidence of damage on the outside. By consistently following good installation practices you can ensure that the electrical properties of each cable you work with will remain according to industry specifications. To assist you during installation, ECS offers the following recommendations as a basic guideline for cable handling and routing.
Note: These recommendations do not replace, but should be used in conjunction with equipment manufacturers' directives.
Basic Precautions
- Never kink or bend electronic cables sharply, nor loop them tighter than what is allowed by the manufacturer's bend radius specifications.
- Never drop anything on, or step directly onto, electronic cables.
- Never pull cabling except in a straight line.
- Never lean on or use electronic cabling as a handle, nor should you apply pressure to, or hang anything from, the cabling.
- Always leave protective caps on connectors during the installation phase to prevent connector contamination or damage.
Stand-offs and Clamps
It is important that you use stand-offs to separate electronic cabling from structures. Using tape or tubing is not an alternative for maintaining proper clearance.
- Always ensure that stand-offs do not restrict electronic cabling in such a manner as to interfere with shock-mounted equipment.
- Do not use moisture absorbent material to fill clamps.
- Damage may occur to electronic cabling by clamping too tightly.
- Clamps should not exceed intervals of 24 inches.
- Clamps should be placed a minimum of 18 inches from spring-loaded ARINC contacts. Clamping cable too closely to spring-loaded contacts may cause side loading, preventing proper mating of connectors and possible contact damage.
- Do not use plastic ties to secure cables, as they may distort the cable's original cross-section through over-tightening. Plastic ties may also fail, causing cables to interfere with movable surfaces.
Routing
- Electronic cabling must be properly supported and routed so that it does not interfere with other wires, cables, or equipment.
- Route cables in such a way that chafing will not occur against the airframe or other components.
- Cables should be routed so that they are not likely to be used as a handhold or damaged by personnel moving about the airframe.
- Electronic cabling should be located so that it is not susceptible to damage by cargo.
- Electronic cabling should be separated from high temperature equipment and heat ducts to prevent insulation breakdown. Use of high temperature insulation material such as FEP or ETFE is recommended. Cables having soft plastic insulation such as polyethylene are subject to deterioration and deformation at temperatures above 85°C.
- Observe all manufacturer specifications for minimum bend radius.
- Provide enough slack to cables during installation to permit ease of maintenance and prevent mechanical strain on cable stand-offs, clamps, and connections.
- Cables should be routed in such a manner so that fluids drain away from connectors.
- Cables that are susceptible to EMI interference should be routed away from any EMI source. EMI increases in proportion to the length of parallel sources and decreases by separation. Cables should employ shielding with a minimum of 85% coverage.
Labeling
- Ensure that all cables are properly identified at each end and at intervals along their length.
- Cables should not be hot stamped, as this may deform the cable and alter its electrical characteristics.
- The most common method of marking cables is the installation of printed sleeves or labels along the length of the cable. Ink jet and laser marking systems are other methods of marking cables. However, these methods are not appropriate for all types of insulation and jacket material.