Furuno FCV-628 Operator's Manual page 44

smoothest. Noise from the propellers also
adversely affects performance and the
transducer should not be mounted nearby.
The lifting strakes are notorious for creating
acoustic noise, and these must be avoided
by keeping the transducer inboard of them.
• The transducer must always remain sub-
merged, even when the boat is rolling,
pitching or up on a plane at high speed.
• A practical choice would be somewhere be-
tween 1/3 and 1/2 of the boat's length from
the stern. For planing hulls, a practical loca-
tion is generally rather far astern, so that
the transducer is always in water regard-
less of the planing attitude.
22
120
120
28
30
68
68
520-5PSD
Thru-hull mount transducer
mounting dimensions
Position 1/2 to 1/3 of the hull from stern.
15 to 30 cm off center line (inside first lifting
strakes.)
Within the wetted bottom area
Deadrise angle within 15°
Suitable transducer mounting locations
24
Unit: mm
BOW
87
520-5MSD
DEEP V
HULL
HIGH SPEED
V HULL
Procedure for installation of the thru-hull
mount transducer (for 520-5PSD/520-
5MSD)
1. With the boat hauled out of the water,
mark the location chosen for mounting
the transducer on the bottom of the hull.
2. If the hull is not level within 15° in any di-
rection, fairing blocks made out of teak
should be used between the transducer
and hull, both inside and outside, to keep
the transducer face parallel with the water
line. Fabricate the fairing block as shown
below and make the entire surface as
smooth as possible to provide an undis-
turbed flow of water around the transduc-
er. The fairing block should be smaller
than the transducer itself to provide a
channel to divert turbulent water around
the sides of the transducer rather than
over its face.
Hole for
stuffing tube
Upper half
Lower half
Saw along slope
of hull.
Construction of fairing block
3. Drill a hole just large enough to pass the
threaded stuffing tube of the transducer
through the hull, making sure it is drilled
vertically.
4. Apply a sufficient amount of high quality
caulking compound to the top surface of
the transducer, around the threads of the
stuffing tube and inside the mounting hole
(and fairing blocks if used) to ensure wa-
tertight mounting.
5. Mount the transducer and fairing blocks
and tighten the locknut. Be sure that the
transducer is properly oriented and its
working face is parallel to the waterline.
37
4. INSTALLATION
BOW