Iridium Pilot TPIM1301, Installation Manual

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2: INST
ALLA
TION
16
Iridium Pilot Land Station Installation Guide
Figure 8.
2.0 m (6.6 ft.) max.
unsupported height
3.2 mm (.125 in.) min.
wall thickness
60.3 mm (2.38 in.)
min. pole diameter
585mm (23 in.)
406mm (16 in.)
203mm (8 in.)
The ODU is supplied with an aluminum mounting bracket used to couple the ODU to a mast. The bracket
provides an access hole to allow the circular ODU/IDU cable connector to pass thru the bracket and connect to
the ODU. A detail of the mounting bracket is included herein to allow a custom mount to be fabricated with a
matching bolt pattern. See Appendix E.
Galvanic Corrosion Protection
Note that the ODU base-plate and the mounting adaptor bracket are constructed out of aluminum. Care must
be taken when mounting the unit to a steel structure. This transition area of dissimilar metals provides for
the potential of galvanic corrosion. The dissimilar metals in the presence of an electrolyte create a very low
voltage battery with the steel acting as the cathode and the aluminum acting as the anode. The battery action
causes an ionic transfer of material from the anode to the cathode. This will cause the aluminum to corrode
and dissolve at an accelerated rate. There are two actions the installer can use to prevent this corrosion.
See Appendix E for an assembly drawing detailing the installation of the ODU with recommended
galvanic isolation.
1. Create an electrical isolation barrier between the ODU base plates and mounting bracket or mast. Take
caution not to damage this barrier during installation. A coating of sealant such as 3-M brand 5200 marine
adhesive between the flanges should be used. Stainless steel isolation washers should be used to keep bolt
head and lock washer from damaging the painted surface.
WARNING
Damage to the paint coating may allow rust to the ODU which could result in failure of the ODU.
This in turn could cause disruption in operation of the Iridium Pilot Land Station device. Avoid
damaging the paint coating. If damage occurs, re-apply appropriate anti-corrosion primer and
paint. Failure to do so could result in serious injury or death.
2. Provide a water barrier to prevent an electrolyte from reaching the area between the dissimilar metals. Again
3-M brand 5200 adhesive, or equivalent, can be used for this purpose to cover all the fasteners and areas
between the flanges.