S9407-AB-HBK-010 Datasheet, PDF (114/276 Pages) Glenair, Inc. – HANDBOOK OF SHIPBOARD ELECTROMAGNETIC SHIELDING PRACTICES

S9407-AB-HBK-010, Rev. 2
Section 6
CABLE SPACING AND SHIELDING REQUIREMENTS
6.1 INTRODUCTION
Electromagnetic Compatibility (EMC) between electrical/electronic equipment and systems is
achieved in part by close adherence to proven installation methods and procedures. This section
provides such a procedure. It can be employed to establish the necessary cable grouping, routing,
spacing, and shielding requirements to ensure EMC in naval installations. The procedure is based on
the following parameters.
a. Radiation characteristics of cables and other interference sources.
b. Susceptibility characteristics of cables in terms of "effective loop area."
c. Sensitivity and operating frequency of equipment connected to the susceptible cables.
d. Shielding effectiveness of shielding conduit.
6.2 SCOPE
This section describes the requirements for cable spacing between susceptible cables and
cables that radiate electromagnetic energy, and between susceptible cables and other interference
sources. The use of shielding conduit is specified only when the spacing requirements cannot be met.
Cable spacing and shielding requirements contained in this section are valid for any shipboard use
where the cable types designated herein are employed. Although the scope of this document is
limited to below-decks shipboard environments, these cable-to-cable spacing requirements apply to
both inboard and outboard installations including the sea water medium.
6.2.1 Cable Types
The nomenclature for cable types employed in this section is in accordance with the following
military specifications: MIL-C-915 (General Shipboard Cable), MIL-C-17 (Coaxial, Twin, and Triaxial
Cables), MIL-C-24640 (Lightweight Cable), and MIL-C-24643 (Low-Smoke version of MIL-C-915).
Cable applications not listed in these four specifications, such as a signal cable used for low-level
power transmission, shall be handled on a "special case" basis. Also, when unlisted cables must be
employed, a "special case" analysis is required. (See paragraph 6.2.2.)
6.2.2 Special Case Situations
Any EMI problem or situation whose resolution is beyond the scope of instruction provided in
this handbook is considered a "special case." Any recommended solutions to special case problems
(supported by sufficient rationale) should be submitted to: Commander, Naval Sea Systems
Command, Code 05K2B Arlington, VA 22242, telephone [phone] or other NAVSEA-
designated authority for approval.
CHANGE 1 of Revision 2
6-1