Flexible Cables

DOE-HDBK-1092-2004

Wires shall be routed away from sharp edges, screw

threads, burrs, moving parts, etc. Holes

through which wires are routed shall have smooth,

well-rounded surfaces, or shall have a

bushing. Clamps for guides used for routing or wiring

shall have smooth, well-rounded edges.

Pressures exerted by such clamps should not cause

cold-flow or otherwise deform the basic

insulation.

9.4.2.1 FLEXIBLE CABLES

Flexible cables may be used:

1. Where flexible cables and attachment plugs are furnished by the manufacturer as part of the

equipment to be mounted in the rack.

2. For connection of stationary equipment to facilitate their frequent interchange.

3. To prevent the transmission of mechanical vibration.

4. Where the fastening means and mechanical connections are specifically designed to permit

ready removal for maintenance and repair.

5. For data processing cables approved as part of the data processing system.

6. For temporary wiring.

Where breaking or loosening of a circuit connection would render an electric shock or could

result in a fire, such connection shall be made mechanically secure. Mechanical security of

connections may be provided by crimped, closed ring or flanged lug, or a wrapping that forms at

least an open U or by cable clamps, or by cable lacing, insulating tubing, or similar means.

9.4.2.2 STRAIN RELIEF

Wiring, cords, or cables shall be provided with strain relief as required to prevent damage.

Additional insulation may be required when the construction of the strain relief may damage the

insulation. The use of type NM (Romex) cable clamps on flexible cords and cables is not

permitted. Use listed or labeled clamps. The use of any metal clamp or other means that may

cause undue stress on the cables within or external to instrument racks is not allowed. Cord and

cable support for AC power cable or other heavy duty or large diameter cables must distribute

the load over a large area of the outer covering of the cable.

9.4.2.3 SEPARATION OF VOLTAGES

Insulated conductors of different circuits shall be separated or segregated from uninsulated live

parts connected to different circuits unless provided with insulation suitable for the highest

voltage involved.

Segregation of insulated conductors may be accomplished by clamping, routing, or equivalent

means that provide permanent separation from insulated or uninsulated live parts of a different

circuit.

Loose strands of stranded internal wiring, connected to a wire-binding screw, shall be prevented

from contacting other uninsulated live parts not always of the same potential and from

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