Sea Tel ST88-21 C/Ku-Band TVRO, Installation And Operation Manual

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Site Survey ST88-21 C/Ku-Band TVRO
2-6
The Satellite Modem, router, VIOP adapter(s), telephone equipment, fax machine, computers and any other associated
equipment should be properly mounted for shipboard use.
Plans to allow access to the rear of the ACU should be considered.
2.8. Cables
During the site survey, walk the path where the cables will be installed. Pay particular attention to how cables will be
installed; such as what obstacles they will be routed around, difficulties that will be encountered and the overall length
of the cables. The ADE should be installed using good electrical practice. Sea Tel recommends referring to IEC 60092-
352 for specific guidance in choosing cables and installing cables onboard a ship. Within these guidelines, Sea Tel will
provide some very general information regarding the electrical installation.
In general, all cable shall be protected from chaffing and secured to a cableway. Cable runs on open deck or down a
mast shall be in metal conduit suitable for marine use. The conduit shall be blown through with dry air prior to passing
cable to ensure all debris has been cleared out of the conduit and again after passing the cable to ensure no trapped
moisture exists. The ends of the conduit shall be sealed with cable glands (preferred), mastic or low VOC silicon
sealant after the cables have been passed through.
Cables passing through bulkheads or decks shall be routed through approved weather tight glands.
2.8.1. ADE/BDE Coaxial Cables
The first concern with the coaxial cables installed between the ADE & BDE is length. This length is used to
determine the loss of the various possible coax, Heliax or fiber-optic cables that might be used. You should
always provide the lowest loss cables to provide the strongest signal level into the satellite modem.
Signal cable shall be continuous from the connection within the ADE radome, through the structure of the
ship to the BDE. Splices, adapters or dummy connections will degrade the signal level and are discouraged.
Be careful of sharp bends that kink and damage the cable. Use a proper tubing bender for Heliax bends.
Penetrations in watertight bulkheads are very expensive, single cable, welded penetrations that must be
pressure tested.
Always use good quality connectors that are designed to fit properly on the cables you are using. Poor
quality connectors have higher loss, can allow noise into the cable, are easily damaged or fail prematurely.
In as much as is possible, don’t lay the coaxes on power cables. Try to have some separation from Inmarsat &
GPS cables that are also passing L-band frequencies or radar cables that may inject pulse repetition noise –as
error bits - into your cables.
2.8.2. Antenna Power Cable
Be cautious of length of the run, for voltage loss issues, and assure that the gauge of the wires is adequate for
the current that is expected to be drawn (plus margin). Antenna power is recommended (but not required) to
be from a UPS, generally the same one that supplies power to the below decks equipment.
Power cables shall comply with the provisions of IEC 60092-350 and -351 as practical. Power cables may be
routed through the same conduit as the signal cable from the junction box to the base of the ADE. Power
cables shall pass through separate radome penetrations from the signal cable.
The power cable shall be continuous from the UPS (or closest circuit breaker) to the ADE connections within
the radome. The power circuits shall be arranged so that ‘active,’ ‘common’ and ‘neutral’ (ground) legs are all
made or broken simultaneously. All circuit legs shall be carried in the same cable jacket.
2.8.3. Air Conditioner Power Cable
If your system includes a marine air conditioner, run an AC power cable to it from a breaker, preferably from a
different phase of the electrical system than that which supplies power to the ADE & BDE. Be EXTREMELY
cautious of length of the run for voltage loss and gauge of the wires for the current that is expected to be
drawn.
Power cable shall comply with the provisions of IEC 60092-350 and -351 in so far as practicable. Power
cable may be routed through the same conduit as the signal cable from the junction box to the base of the
ADE. Power cables shall pass through separate radome penetrations from the signal cable.
The power cable shall be continuous from the closest circuit breaker to the ADE connections within the
radome. The power circuits shall be arranged so that ‘active,’ ‘common’ and ‘neutral’ (ground) legs are all
made or broken simultaneously. All circuit legs shall be carried in the same cable jacket.