184.108.40.206 Paper-Insulation. Use paper-insulation for low ionization, long
characteristics under temperature variations. As with varnished-cambric
insulation, paper-insulation requires a suitable protective metallic-sheath.
It may be specified as a contractor's option when existing cables are paper-
insulated, or as a requirement when the extra cost is justified because
neither XLP nor EPR provide the required qualities.
220.127.116.11 Nonmetallic. Provide nonmetallic sheaths which are flexible,
moisture repellent, and long-lasting.
18.104.22.168 Metallic. Cables exposed to mechanical damage or high internal
pressure require a metallic sheath, such as lead, aluminum, or steel. Certain
insulations require such protection in all cases, such as paper and varnished-
Cable Coverings. For corrosion protection of metallic sheaths,
specify a suitable covering or jacket.
Shielded Cables. Provide shielding of a medium-voltage distribution
cable to confine the electric field to the insulation itself, and to prevent
shielding is required on all nonmetallic-sheathed cable rated 2 kV and above
and all metallic-sheathed cable rated 5 kV and above. Shields should be
grounded to reduce the hazard of shock. Grounding is required at each splice
and at each termination, otherwise dangerous induced shield voltages may
Cable Splicing. Provide cable splices in accordance with NFGS-
16301. Aluminum-to-copper and nonmetallic-jacketed to lead-covered cable
connections are easily made when connectors and splicing materials are
correctly utilized and installed so as to prevent any galvanic action or oil
migration which might occur. Such transitions are not permitted when
installing new lines; however, splices of this type may be necessary for
connections between existing and new work.
Cable Fireproofing. Fireproof cables operating at 2,200 V or over,
or exposed to the failure of other cables operating at these voltages, in
manholes, handholes, and transformer vaults, as required by NFGS-16301.
Exceptions may be made where physical separation, isolation by barriers, or
other considerations permit, if approved by the local Naval Facilities
Engineering Command (NAVFACENGCOM) having jurisdiction.
Cable Identification. Tag cables in all manholes to identify
circuity, cable size, cable conductor and insulation type, voltage rating,
manufacturer, and date installed. Cable identification provided on the
insulation by the manufacturer need not be repeated unless covered up by
fireproofing. In handholes and at other termination points only a circuit
identification is required.