Furuno FV-110, Operator'S Manual, Page: 195 / 240

Alternative grounding for steel hulls
F-3
electrical contact to the hull. Use serrated washers when securing the mounting bolts and
seal the joint with protective coating to avoid corrosion.
It is always recommended to establish the shortest possible grounding path e.g. on steel
hulls the ADU should be grounded directly to the hull
2
. However, due to the fact that this
is not possible on e.g. fibreglass hulls (nor is it preferable on aluminium hulls) a number
of alternative grounding methods are suggested in the following paragraphs.
F.3 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.
F.3.1 To ground the ACU
The ACU should preferably be grounded to the ship with the short cable. Further, the
ACU must be grounded at its grounding stud in order to ensure a proper grounding if the
short ADU cable is disconnected.
The ground connection can be established either at the hull (recommended) or at a
dedicated RF ground if available (alternative).
Figure F-2: Grounding the ADU
Note
For optimum grounding use the mounting bolt located closest to the ADU cable
plate, see
To ground the ADU on page 2-24.
2. Please note that the ADU ground connection is made at the same electrical ground potential
as the ACU.
Antenna bottom
Mounting base
M12 bolt
Serrated washer
(stainless steel)
(stainless steel)
Important
However, bear in mind that the ADU ground
connection is to be made at the
same electrical
ground potential as the ACU (see To ground the
ADU ).