Alternative Grounding For Steel Hulls - KVH Industries TracPhone F55 Installation Manual

Appendix G: Grounding and RF protection
G.5 Alternative grounding for steel hulls
The following guidelines assume a two-wire, isolated grounding
arrangement; that is no part of the circuit, in particular the battery negative, is
connected to any ground potential or equipment.
G.5.1 Grounding the BDU
The BDU must be grounded to the ship by means of the Antenna Pigtail Cable
and the Grounding Kit (accessories, TT-403088A-930). Further, the BDU must
be grounded at its grounding stud in order to ensure a proper grounding if the
pigtail is disconnected.
The ground connection can be established either at the hull (recommended)
or at a dedicated RF ground if available (alternative). However, bear in mind
that the ADU ground connection is to be made at the same electrical ground
potential as the BDU (see Grounding the ADU).
The BDU provides galvanic isolation (as required) from its input power
terminals to the chassis/grounding stud. This way the isolated grounding
arrangement is maintained.
G.5.2 Grounding the ADU
BDU grounded at the hull (recommended):
In this case the ADU must be grounded to the ship via one (or more) of its
mounting bolts. Make sure to remove painting, dirt, grease etc. at the
mounting holes in order to make good electrical contact to the hull. Use
serrated washers when securing the mounting bolts and seal the joint with
protective coating to avoid corrosion.
BDU grounded at a dedicated RF ground (alternative):
In this case the ADU must be grounded by means of a separate ground cable.
The ground cable must be routed parallel and in close proximity to the
shielded coax cable hence connecting the ADU to the BDU Grounding Kit. A
tinned heavy gauge wire (min. 6 mm2) can be used for this purpose - see
page 119.
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Alternative grounding for steel hulls