Alternative ground for steel hulls
B-4
Appendix B: Ground and RF protection
98-146706-A
B.2.2
To ground the ADU
To ground the ADU do as follows:
1. Ground the ADU to the ship/hull via one or more of its mounting bolts.
2. Make sure to remove painting, dirt, grease etc. at the mounting holes in order to make
good electrical contact to the hull.
3. 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.
B.3
Alternative ground 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.
B.3.1
To ground the ACU
To ground the ACU do as follows:
1. Ground the ACU preferably to the ship with the short cable.
2. Further, ground the ACU at its grounding stud in order to ensure a proper grounding if
the short ADU cable is disconnected.
Figure B-2: Grounding the ADU
Note
For optimum grounding use the mounting bolt located closest to the ADU cable
plate, see
2. 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)
SAILOR900Ka-IM-98-146706.book Page 4 Thursday, July 16, 2015 11:07 AM
