COBHAM Sailor 900 VSAT, Technical Manual

Page: 314 / 356

Alternative grounding for steel hulls
F-4 Appendix F: Grounding and RF protection 98-133966-G1
The ground connection can be established either at the hull
(recommended) or at a dedicated RF ground if available (alternative).
The ACU provides galvanic isolation (as required) from its input power
terminals to the chassis/grounding stud. This way the isolated
grounding arrangement is maintained.
F.3.2 Grounding the ADU
F..3.2.1 Terminal grounded at the hull (recommended)
In this case the ADU is 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.
F..3.2.2 Terminal grounded at a dedicated RF ground
(alternative)
In this case the ADU is grounded with a separate ground cable. The
ground cable must be routed parallel and close to the shielded coax
cable connecting the ADU to the ACU grounding kit. A heavy gauge
wire with tinned strands (min. 6 mm
2
) can be used for this purpose.
Important
However, bear in mind that the ADU ground
connection is to be made at the
same electrical
ground potential as the ACU
(see Grounding the
ADU
).
Note
For optimum grounding use the mounting bolt located closest to the ADU cable
plate, see
Grounding the ADU
on page 3-22.
Note
The ADU must be electrically isolated at its mounting bolts
by means of shoulder bushings and washers ensuring the
isolated RF ground - see
Isolation of the ADU from the
mounting base
on page F-11.
SAILOR900TM.book Page 4 Monday, September 16, 2013 11:01 AM