Wire Selection

In most cases during a chassis design individual wires will be required to run between different components within the chassis. Individual wires from the power supply to the power switch, or wiring to indicator lights is required and common.

Design Hint; Always choose a wire diameter that meets or exceeds the electrical requirements of the wire. AWG Wire Sizes.

When possible be sure to use wires that are color coded. Always color code any power lines to indicate their function.

Design Hint; Color coding power lines is a safety issue and helps with system debug. Never take short cuts with safety issues.
Wire Insulation Color Coding, by function or voltage.

Individual data wires are not always color coded but color coding will assist with any debug or rework that may be required. In many cases every wire terminating in a connector are the same color. Using the same color for all the data wires within a cable saves money, assembly time and lowers the amount of line items in the parts list. However cable assemblies containing wires of all the same color hinders debug.
Also refer to the cable assemblies guidelines.
Similar topics in this section cable assemblies manufacturers.
Or Cable Derating Guide Lines

Cable Assemblies , next page


Be sure to specify the cable insulation if it's important to the finished design. A military spec chassis may preclude the use of PVC because of the amount of smoke PVC produces when it catches fire. Changing from PVC to Teflon insulation could add cost to the system at the last minute.

If the individual wires need a particular color code, or if a wire bundle need to be a certain wire color code than call that out in the chassis specification.
Fiber cables are also color coded based by function.
Guidelines for Color Coding Fiber Cable, or fiber insulation.

Design Hint;
Do the cables require a particular Back Shell, and will the back shell and cable bend radius fit within the chassis. Is there room behind the chassis door and front panel of the card chassis, or behind the chassis between that panel and the rack door.

Cable Ferrites Manufacturers
Connector Environmental Protection Ratings
How To Specify a Equipment Chassis; Index page

Design Hint:
If the design can afford it, allows use a shielded cable. Assuming bend radius and cable size does not come into play, a shielded cable will reduce the noise generated within the chassis. The addition of the shield also adds thickness and weight to the cable and decreases flexibility.

PC motherboard

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