Recommendations
98-141779-G Appendix C: Ground and RF protection C-3
CCCC
C.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.
Figure C-2: Grounding the ADU
For optimum grounding use the mounting bolt located closest to the ADU cable
plate, see To ground the ADU on page 3-20.
2. Note that the ADU ground connection is made at the same electrical ground potential as
the ACU.
Antenna
bottom
Serrated washer
(stainless steel)
Mounting
base
M12 bolt
(stainless steel)