Furuno FSV-84 - Manual (Page 9)

1-1
1. MOUNTING THE EQUIPMENT
1.1 Hull Unit
Note 1: The raise/lower control box on the hull unit contains a motion sensor. Therefore,
never drop the hull unit.
Note 2: Handle the transducer carefully. Shock will damage its sensitive components.
1.1.1 Mounting considerations
Decide the location of the hull unit through consultation with the dockyard and ship owner.
When deciding the location, the following points should be taken into account.
• Choose an area where propeller noise, cruising noise, air bubbles and interference from
turbulence are at a minimum. Generally, the point at 1/3 to 1/2 of the ship’s length from the
bow on or near the keel is optimum. On-the-keel installation is advantageous for
minimizing oil consumption in comparison with off-the-keel. If the hull unit can not be
installed on the keel, the center of the retraction tank should be within 600 mm of the keel
to prevent a rolling effect. For large ship with deep draft, the hull unit can be installed at
the bow.
1/2 1/3
Within 600 mm
Hull unit mounting location
• Choose a place where the hull bottom is flat and the draft is sufficiently deep. Normally,
the transducer should protrude at least 500 mm beyond the keel to minimize the effect of
air foam and bubbles.
• Choose a place where interference from other transducers is minimal. The hull unit should
be at least 2.5 m away from the transducers of other equipment.
• No obstacle should be in the fore direction since it causes a shadow zone and aerated
water, resulting in poor sonar performance.
• The physical distance between the hull unit and the transceiver unit should be no more
than 5 m.
• The space shown in the figure on the next page is required around the hull unit for wiring
and maintenance.
• If the ambient temperature around the unit will be below 0 °C, provide the sonar
compartment with a heater to keep the temperature above 0 °C. See the next page for
details.