Hull Unit - Furuno CH-250 Installation Manual

1.3

Hull Unit

NOTICE
The flange of the retraction tank
must be parallel with the waterline.
The keel of the ship may not be
parallel with the ship's draft.
1.3.1 General mounting considerations
•
Noise and air bubbles will affect performance.
•
Do not turn on the equipment with the transducer exposed to air. Exposing the transducer to
air may damage it.
1.3.2 Installation position considerations
Discussion and agreement are required with the dockyard and ship owner in deciding the
location for the hull unit. When deciding the location, take into account the following points:
•
Select an area where propeller noise, cruising noise, bubbles and interference from
turbulence are minimal. Generally, the point at 1/3 to 1/2 of the ship's length from the bow or
near the keel is the best. If the hull unit cannot be installed on the keel, the center of the
retraction tank should be within 1 meter of the keel to prevent a rolling effect.
For a wooden vessel: Install the hull unit off the keel.
For other than a wooden vessel: On-the-keel installation is advantageous in comparison with
off-the-keel.
Mounting range 1/3
1/2
•
Select a place where interference from the transducers of other sounding equipment is
minimal. The hull unit should be at least 2.5 meters away from the transducers of other
sounding equipment.
•
An obstacle in the fore direction not only causes a shadow zone but also aerated water,
resulting in poor sonar performance. Be sure to locate the transducer well away from any
obstacle in the fore direction.
Install the hull unit away from the
places subject to water splash and
rain.
Fire or damage to the unit can result.
If necessary, waterproof the unit.
For a wooden vessel
Retraction tank
Keel
Within 1 m
8
NOTICE
For other than a wooden vessel
Keel
Retraction tank
Within 1 m