Chapter 4 Installation and Wiring
PAGE 4-27
4-5-3 Cable Installation Guidelines
Improper installation of cables can reduce cable life expectancy drastically. The following guidelines
should be used when installing cables.
• The cables must be prepared for installation without twists, bends or kinks. Upon unpacking the
cables, any tie wraps used in shipping should be removed.
• Before inserting the cables in the cable tray, cable track or other overhead suspension, it is
important that the cables be laid out or hung prior to installation long enough to relax any stresses
and remove any “memory” resulting from packaging, transit or storage. If the cables cannot be
relaxed, they should be shook out by grasping the cable length at its mid point and shaking the
cables as you move to each end. Then, wrap the end of each cable with masking tape and make
alignment marks on the top of each end. Maintain this alignment throughout the installation to
assure cable is not being twisted.
• The minimum recommended bending radius of the cable should not be exceeded. The minimum
bend radius is calculated by multiplying the cable’s outer diameter by ten (Rmin = O.D. x 10).
When multiple cables are run together, the largest diameter cable in the bundle should be used
for calculating bend radius. Minimum bend radius must be increased when repeated flexing
occurs at a given point on the cables.
• Use the most direct path when routing cables.
• Do not weave cables between or wrap around one another.
• Route cables and connectors away from liquid of any type.
• Protect cable connectors from any impact or abrasion that may cause damage (IE: pulling cables
through cable tray and dropping cables to the floor).
• Check cable route for possible chafing or abrasion points. Re-route or protect cable at these
points with a nylon cable wrap or similar means to avoid future cable damage.
• The use of plastic cable ties (ty-wraps) should be avoided if possible. The use of Velcro straps is
preferable. If the use of plastic cable ties cannot be avoided, the following practices should be
followed:
o Cables should not be tied so tight as to cause indentations in the cable jacket.
Flexible cables are designed to move inside their cable jacket. If this movement is
restricted, wires in the cable may become stressed and break.
o Plastic cable ties around grouped cables should be used minimally so that cables
have the ability to move individually rather than all as one.
o An acceptable method is to include the use of a flexible tubing or sleeve between the
plastic cable tie and the cable(s).
• Do not tie or hang anything, whatsoever, from tool cables.
• Avoid running cables directly next to high voltage or high frequency lines.
• Cables must be supported near connectors in panel and at tool to avoid strain on connection
points.
• Certain tool operations may have foreseeable cable damaging aspects which are unavoidable. In
these situations a shorter “extension” cable can be provided with the expectation of replacing this
intermediate, less expensive cable as required. The use and proper placement of an “extension”
cable will also make cable replacement less time consuming.
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