Simrad SP60 - REV D, Installation Manual

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Cable layout and connections
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851-164574 / C
Radio Frequency interference
All cables that are to be permanently installed within 9 m (30 ft)
of any source of Radio Frequency (RF) interference such as a
transmitter aerial system or radio cabin, must, unless shielded by
a metal deck or bulkhead, be adequately screened by sheathing,
braiding or other suitable material. In such a situation flexible
cables should be screened wherever possible.
It is important that cables, other than those supplying services to
the equipment installed in a radio room, are not installed through
a radio room. Cables which must pass through a radio room must
be screened by a continuous metal conduit or trunking which must
be bonded to the screening of the radio room at its points of entry
and exit.
Physical protection
Cables exposed to the risk of physical damage must be enclosed in
a steel conduit or protected by a metal casing unless the cable’s
covering (e.g. armour or sheath) is sufficient to protect it from the
damage risk.
Cables exposed to an exceptional risk of mechanical damage (for
example in holds, storage-spaces and cargo-spaces) must be
protected by a suitable casing or conduit, even when armoured, if
the cable covering does not guarantee sufficient protection for the
cables.
Metallic materials used for the physical protection of cables must
be suitably protected against corrosion.
Grounding
All metallic cable coverings (armour, lead sheath etc.) must be
electrically connected to the vessel’s hull at both ends except in the
case of final sub-circuits where they should be connected at the
supply end only.
Grounding connections should be made using a conductor which
has a cross-sectional area related to the current rating of the cable,
or with a metal clamp which grips the metallic covering of the
cable and is bonded to the hull of the vessel. These cable coverings
may also be grounded by means of glands specially intended for
this purpose and designed to ensure a good earth connection. The
glands used must be firmly attached to, and in good electrical
contact with, a metal structure grounded in accordance with these
recommendations.
Electrical continuity must be ensured along the entire length of all
cable coverings, particularly at joints and tappings. In no case
should the lead-sheathing of cables be used as the only means of
grounding cables or units.